Eric C Emms Limited

Describing gems

2012-01-06T12:56:00.002Z

To help the gem consumer understand what a gem is, ie its nature, whether it is man-made or not, and whether it has been treated or not, gem specialists debate the correct wording or nomenclature to be used so that the consumer can buy with confidence.
This debate on the most useful wording to describe gems has endured for decades. Gemmologists look toward CIBJO and other industry organisations for guidance. A group of gem laboratories publish Information Sheets to explain wording used on gem laboratory reports. The latest sheets can be read here.

IDEX Online News - AGL Issues Warning About Irradiated Colombian Emeralds

2012-01-06T12:45:00.000Z

IDEX Online News - AGL Issues Warning About Irradiated Colombian Emeralds

Cert GA

2011-02-06T12:36:00.000Z

Passed your first year (Foundation) Gem-A exam and couldn't take or pass the second year (Diploma) exam? Now you can have letters after your name. Not quite the "FGA" but Gem-A has announced you can add "Cert GA" to your business card if you passed the first year since 2004.

Our new website

2010-09-02T17:06:00.000+01:00

Our new website is (almost) complete. Comments welcomed from Opera, Firefox and other browser users.
Thanks, Eric.

What to do after the summer break

2010-08-27T17:03:00.000+01:00

After the Summer break comes the period running up to Christmas. How are you going to spend your time? What do want to do?

Perhaps brush up your educational or experience elements of you CV. Or add further steps in that plan called Personal/Professional Development? Or just do something that interests you and is fun. Well, please consider taking one of our short gem courses this Autumn.

In Hatton Garden, the home of the UK gem and jewellery industries, we are holding:

Our latest week-end practical diamond grading course starting on 30^th October.

Our two-day introduction to Coloured Stones (with visits on the third day to the exceptional gems in the museums in South Kensington) starting 25th September.

Our one-day workshop on the current wholesale values of coloured stones on 25^th October.

Our two-day rough diamond course starting on 1^st October.

Further details on the content of the courses, booking details and fees are available from our upgraded website www.ericemms.com or from me on 07973 725 266.

Hope to see you soon to enjoy the quality and value of gems!

Recommended book: Diamond Handbook.

2010-08-01T10:25:00.002+01:00

The first book one should buy on the subject of diamond evaluation.

At my diamond courses I offer in Hatton Garden and around the UK participants often ask me which book on diamonds I would recommend. Surprisingly there are not that many books in print which explain the diamond topics of my courses, namely how to identify diamond, its look-alikes and treatments, how to judge quality and how to price the gem. The best book available is Diamond Handbook – a practical guide to diamond evaluation by Renee Newman. You can buy it here.

Gems from India and Ceylon

2010-07-18T12:15:00.002+01:00

Below are my notes taken (quickly) at Jack Ogden’s talk held recently at GIA London. Details have not been checked with the speaker or third parties and are prone to error. I welcome corrections.

Eastern Promise: a history of the gem trade from India and Ceylon

Introduction

Gems have been traded throughout Asia for thousands of years. A jewel from Ur (in modern Iraq) dated 2600 BC has beads of lapis lazuli mined from what is now Afghanistan.

Up to 1730s India was the only major source of diamonds. Indian citations claimed that very few large diamonds (over 15ct) were found until 16C.

First Mediterranean use of diamonds was in Greece in approx. 500BC – used as tool to engrave upon gems such as chalcedony.

The earliest reference to Indian gems in the West was by a Roman writer in the early centuries AD quoting a Greek writing in the 5^th century BC of “a garland of golden Indian gems”

Trade in Indian gems started at the time of Alexander the Great. He from N. Greece in approx 300BC conquered vast parts of the Persian Empire and reached the borders of India. At this time Theophrastus, the Greek philosopher, mentions diamonds. Another Greek around this time wrote a book on the value characteristics of diamond: shape, colour and brilliance.

The next major Roman writer mentioning Indian diamonds was Pliny the Elder who died in AD79

Hundreds of Roman ships sailed to India via the Red Sea. 30 million dollars per year (at today’s prices) worth of diamonds were imported into the Roman Empire from India at this time. The gems were sold within the Empire at 10 times more this amount.

Written description of the gem trade in India is limited. Evidence comes from jewels themselves. A ring discovered recently in Afghanistan from 300BC shows two diamond octahedral crystals mounted in a ring. This is the earliest example of a diamond ring.

Ogden mentioned other finds of diamond rings: a Roman ring dated 175AD and a 3^rd century ring found in Syria showing a diamond crystal – diamonds could not be faceted at this time. An early imitation of diamond from the 3^rd century is ring with rock crystal fashioned to imitate a diamond

In the 13^th century Marco Polo described Indian diamonds – the fine ones were kept for the Indian rulers and the lesser ones were sold.

Campaigns of Genghis Khan made possible the establishment of the Silk Route, the overland trade path from China to the borders of Europe. A quote from 1795 claimed diamond merchants travelled in safety when on the Silk Route. An Interpreters’ Book of translation of business words in three languages for use by traders on the Silk Route gives translations for word diamond.

Mentioning sapphires, a 2^nd – 3^rd century Roman Necklace has bean-shaped sapphire beads probably from India. In 5^th -6^th century Roman times - pale blue drop shaped drilled beads from Ceylon fashioned from the broken bipyramidal prisms were used in jewellery. Many sapphires at this time were worked with a drill to remove surface reaching inclusions, resulting in deep surface grooves. This work was done in India at source since the 3^rd century.

Sapphire was the most popular gem in Europe in Medieval jewellery but the gem was not popular in Islamic lands.

The 15^th century Middleham jewel with a sapphire cabochon found in England.

Faceting of gems became more complex during the 15^th century with rose-cut sapphires appearing in European jewellery.

Rubies were not common in Ceylon gem gravels. None have been found in ancient jewels and very few in later jewels. Many red stones called rubies in medieval jewellery are perhaps garnets or spinels. Emeralds at this time were from Egypt.

In the 11^th century the heating of rubies is mentioned in texts. “Rubies were heated in crucibles specifically designed for heating gems”. It was discovered the yellowish tinge of sapphires could be removed by heating.

Ceylon sapphires and Indian diamonds were set in jewellery made in England in the 14^th century as part of dowry for the English Queen Blanche to be married to a Munich prince.

Muslims preferred red stones – spinels from Badakhshan (Afghanistan). Source exploited from 1524 – found after an earthquake. The 14^th century gem, the Black Princes Ruby is a 170 carat spinel now mounted in the Imperial State Crown.

Gem Values –

In 14^th century India diamond was the most expensive gem – an 18 carat diamond was valued at 3million pounds (current values). Emeralds were much cheaper than rubies.

Spinels were more costly than chrysoberyl cat’s- eyes, which were more expensive than sapphires. A 15 carat sapphire was valued at just £200.

In the 15^th century the silk route was closed thus the sea route to Asia was opened up. Many gems were brought into Europe from Goa, India by this route. Madras was an important port for English commerce.

Pearls

Earliest pearl in Europe from 300BC is a large 2cm diameter pearl from Ceylon found in Cyprus now in the British Museum. Enormous prices were paid for pearls. In 1330 a European writer states 8000 boats were employed in pearl fishing in the Gulf of Mannar (between India and Ceylon).

Tavernier brought back diamonds and pearls during his travels to India in the 17^th century.

The production of Indian diamonds was less than 5000 carats per year. The low global volume exploded with the discovery of Brazilian and Southern African diamond deposits. In 1870s 100,000 carats per year were exported from South Africa causing a temporary price drop until the ‘new rich’ of the industrial America took up the supply.

In the 16^th=17^th centuries faceting of gems became popular. Rubies were common in Europe as new sources in Burma came on stream causing a price drop of rubies in India. Sapphires at this time were rare in European jewellery. Sapphires came popular in Europe only in late 19^th century.

In jewellery the settings of table-cut coloured stones followed the irregular outline of the gems. Tops and sides of gems were faceted, bottoms were left unpolished to preserve weight. Faceting was carried out on bow-driven polishing wheels

The Cheapside Hoard (discovered in London in 1913) a 17^th century goldsmith’s stock in trade contained large gems from India and Ceylon.

A Welshman, Elihu Yale, went to Madras with the East India Company. He made a vast fortune trading in diamonds and in the early 18^th century helped bequeath the US university that bears his name.

Mogul court was importing emeralds from South America just a generation after their discovery. Tavernier writes of this importation.

Coral was imported into India from the Mediterranean for centuries. It was highly valued in the East. An East India Company document shows coral being exported to India, sold there and diamonds being bought for export with the funds.

Exporting gems from Ceylon was disallowed upon pain of death.

In 1796 the British moved into Ceylon (previously Dutch and Portuguese). John Davy 1821 gives an account of the best cat’s-eyes from Ceylon but thought the gem industry not to be profitable.

In 1875 the Prince of Wales visited Ceylon. His visit created an interest in the island and its gems and by 1886 new British companies were dealing in Ceylon gems. Tourists en route to/from the Orient bought gems in Ceylon in a Colombo hotel. Most gems were glass!

Rough Diamonds course

2010-07-16T15:52:00.000+01:00

I'm delighted to announce the date of our two-day rough diamonds to polished course. It will be held in Hatton Garden, London from 30th September to the 1st October. Further details on our website

Gem Quality and Values

2010-07-06T13:29:00.000+01:00

I enjoyed seeing some of my former lab clients at my latest Gem Quality and Values workshop run with Tracy Jukes in Hatton Garden on the 5th July. Retailers from the North East, West and South East England discussed the following topics with reference to a large variety of coloured stone samples:

Gem Descriptions
The current problems in describing gem colours, varieties (e.g. Paraiba), treatments (e.g. filling of fissures in ruby and coated topaz) and synthetic and imitation stones

Gem Qualities
· What qualities are attractive ? How to describe gem quality to suppliers and customers?
· Examples of any one gem variety, e.g. ruby, seen in the marketplace do vary in quality. How do we judge gem quality?
· How does quality affect the price of gems? How does the origin of the gem affect prices?

Gem Values
What are the current prices of coloured stones? Price and value: what’s the difference?
· How do the different types and extent of gem treatments (e.g. heat, fissure-filling, etc) alter gem values?
· How does the availability of Man-made gems (both synthetic and imitation stones) affect the values of their natural (mined) counterparts? Are there consumer awareness and a demand for Man-made gems?

Consumer issues
Coloured gem certification and insurance documents
Care of jewellery: durability of gems and stability of their treatments
Ethical gems and ethical jewellery.

The next workshop is on Oct 25th. See my website for further details and you can book here

July – rubies, water lilies and dog days

2010-06-21T16:23:00.000+01:00

All three are associated with the month of July.

Plenty of rubies are to be seen at our next Gem Quality and Values workshop. Following our successful launch earlier in the year we are holding the second one in Hatton Garden on Monday the 5^th. The day offers a rare chance to examine current gem treatments and appreciate various qualities and current prices of coloured stones.

Our popular and well regarded week-end Practical Diamond Grading courses continue; the latest is being held at the end of the month, on the 24^th & 25^th in Hatton Garden.

Please see our Teaching section of our website for details, how to book and pay.

In mid-July we are presenting again a number of diamond courses designed specifically for the needs of jewellers and pawnbrokers, in Leeds and Manchester.

The future of the diamond industry

2010-06-08T11:39:00.000+01:00

One person's view of Rapaport's view of the market
http://www.luxist.com/2010/06/07/reporting-from-the-rapaport-conference-what-is-the-future-of-di/

Summer's here...

2010-05-24T12:00:00.000+01:00

“Summer’s here and the time is right for dancing in the street”. Well, perhaps, learning more of gems! As always with our short, practical gem courses we aim to convey the beauty, rarity and value of precious stones to all who love gems and jewellery.

On the evening of Thurs 10^th our Whisky & Diamonds event is hosted by the Scotch malt Whisky Society, off Hatton Garden. Have fun learn the similarities (and differences) between the qualities of the wee drams and the King of Gems. Click here for details.

Holts Academy of Jewellery holds their latest two-day diamond course on the 12^th & 13^th. I shall be teaching the identification of diamonds, how to judge quality and how to value diamonds. When considering purchasing a diamond the consumer wants to know they are getting “the real thing” and obtaining “value for money”. This weekend course addresses those concerns. Click here for details.

I will be teaching a bespoke course for London-based pawnbrokers on the 22^nd & 23^rd. This two-day practical identification and grading event has been organised by the National Pawnbrokers’ Association. Click here for details.

Hatton Garden Festival 2010.

2010-05-17T13:21:00.000+01:00

On Saturday 12^th June Hatton Garden will be closed off to traffic to make way for the annual street festival celebrating the jewellery quarter that is Hatton Garden. The festival will give visitors a fun, behind-the-scene access to the fascinating world of our gem and jewellery industry.

I shall be presenting a two-day Practical Diamond Grading course on behalf of Holts Academy of Jewellery on the day at Langdales Jewellery Centre, located close to the Education Zone of the festival, continuing on the following day.

Visitors to the Education Zone will have a chance to get hands-on with workshops and seminars, including “The Enchanting Allure of Pearls” and “Jewellery Through the Ages”, create their own jewel in one of the workshops in the Discovery Zone, visit the showcase “Jewellery As A Vocation” and have fun with the children with live music, a Punch & Judy show and a gem hunt at the Family Zone.

photographing demantoids

2010-05-05T15:37:00.000+01:00

Our core motivation to present our short gem courses is to emphasise the rarity and beauty of diamonds and coloured stones. As a further extension of this initiative, due to demand we plan to offer rare, unaltered coloured stones to discriminating gem connoisseurs.

Our first offers will be demantoid garnets from Russia and rubies from Mogok, Burma. All gems were acquired years ago and I have tested them to confirm they have not been altered. During our marketing set-up a problem arose when I attempted to photograph my demantoids for website illustrations. Rendering faithfully the hues of green gems rich in chromium (emerald, alexandrite and demantoids) in a photograph are notoriously difficult: my eyes saw an attractive vivid green of medium tone but my camera produced an ugly grey-green of poor saturation and tone. My photographic efforts do not do justice to the beauty of my gems. So how best to illustrate my demantoid garnets?

“Here We Go Gathering Gems In May”.

2010-04-30T11:10:00.002+01:00

May sees us holding our latest Practical Diamond Grading Course in Hatton Garden over the weekend of the 22^nd and 23rd. You will be introduced to the identification of the gem (spot CZ, moissanites, laser-drilled diamonds and fracture-filled stones), how to judge quality through the 4Cs, go beyond these four to judging the beauty of diamonds by assessing what makes for the ‘sparkle’ of diamonds. We finish the weekend with a look at the current rarity and prices of polished diamonds.

On Sunday 16^th our Gem Inclusion Master Class is for those who know a little of gems (perhaps having explored my Coloured Stones course) and wish to learn how the internal world of gems (please don’t call them flaws!) helps judge their excellence. No dull gem constants are taught: this is not a gem testing workshop. Remember inclusions are great fun to look at! Use our gem stereo-microscope for the day!

The National Association of Goldsmiths has asked me to teach my Diamond Grading Course for Retailers (and Valuers) at their HQ in the City of London on Tues 18^th and Wed 19^th. The course is tailored for the retailer who wishes to sell more diamonds through acquiring greater product knowledge and it’s a great opportunity to network with fellow retailers. More details and booking information from Amanda White at the NAG on 020 7613 4445 or amandaw@jewellers-online.org

On the 26^th we continue our bespoke gem courses for pawnbrokers hosted by the National Pawnbrokers Association.

For further details contact us on 07973 715 266 or ericemms@aol.com and search online for ‘Eric Emms’.

Looking at the qualities of coloured stones and their values.

2010-04-19T15:26:00.003+01:00

On Sunday 18^th April I hosted my first Gem Quality and Values Workshop in Hatton Garden. Retailers, jewellery valuers and dealers attended the day to examine a large spread of gems of various qualities supplied by Tracy Jukes, each priced at current UK wholesale prices per carat.

We discussed how the variation of colour (saturation, tone and distribution), transparency, clarity and cutting precision and style influences prices. The importance of certification of prized gems, e.g. padparadscha sapphire and Paraiba-type tourmaline was considered with examples.

How the variation of supply of gems mined over time, the demand by retailers and the public for certain gems and how current political and legislative developments influenced current UK prices of gems were considered with reference to examined gem varieties.

The day finished with Tracy showing examples of current ruby, sapphire and emerald treatments and Man-made stones. Their UK prices were noted and future likely trends in demand discussed.

The next workshop is on Monday 5^th July.

The New Gemmology

2010-03-04T15:31:00.001Z

The primary task of a gemmologist is to identify a gem. When one considers the extent of treatments and synthetic stones in the marketplace and the advanced gemmological knowledge (a basic grasp in solid-state physics helps) and access to high-tech analytical tools gemmologists needed to correct identify a gem, gemmology cannot be now anything else than "scientific". This does turn off many from studying gemmology.

But I consider another task for a gemmologist is to explain gem identity, quality and beauty to the industry and the public. I call this task the New Gemmology and I find it fun and hugely rewarding. Read here what the Financial Times thought about the way I talk on gemmology.

Antique jewellery and coloured stones courses in 2010

2010-02-19T15:11:00.001Z

In 2010 I am offering a number of short practical gem courses that push beyond my core course content of gem quality, identity and beauty. Acting on feed-back from past course attendees I am delighted to announce two new one-day events:

In partnership with Joanna Hardy, former Sotheby’s jewellery expert and a current jewellery specialist on the BBC TV Antiques Roadshow, we will be presenting the “Magical World of Antique Jewels and Gems”. This exciting and unique day will be held in Knightsbridge, London. I will look at the complexities of the gem world, what to look for and how to appreciate nature's marvels. Followed lunch at The Capital Hotel, Knightsbridge, Joanna will take you on a journey through the Art Deco period and Famous Jewellery Collections, looking at the gems in the pieces. The day will finish with champagne and canapés.

First 2010 date: APRIL 19th 2010

£390

To book please contact Laura Styles at The Capital Hotel: 020 7591 1215.

In addition, in partnership with Tracy Jukes, a leading UK gem dealer in Hatton Garden, I will present a one day workshop on “Gem Qualities and Values”. During a day of handling coloured stones, I will lead attendees through topics such as current gem treatments and the latest simulants and synthetics and how gem quality is judged. Tracy will discuss current values of commercially important gems, how treatments affect value and what determines current fluctuations in gem prices.

First 2010 date: APRIL 18th 2010. Places are limited

£125

To book please see my website www.ericemms.com or contact me on 07973 725 266.

2010 Diamond and Gem Courses

2009-12-06T12:57:00.000Z

Our last day of training of 2009 is the final day of our three-day ‘Exploring Gemstones’ course on Friday 11^th December when we view and discuss the beauty and quality of the spectacular gem exhibits at the Natural History Museum and the Victoria & Albert Museum in South Kensington, London.

As 2009 draws to a close, we can consider our training during the year to be successful. We have taught diamond and coloured stones courses in Hatton Garden, held one-to-one sessions in association with Holts Academy. We have offered practical diamond sessions for pawnbrokers in nine towns and cities in England and Scotland, in association with the National Association of Pawnbrokers. We presented diamond grading courses for retailers in the City of London for the National Association of Goldsmiths and we have run bespoke corporate training events for jewellers in five venues in London and the provinces.

Participant feed-back on our 2009 course contents has been extremely positive and for 2010 not only will we repeat our short gem course programme in association with our three educational partners but also, for the first time, we are hosting our own organised diamond grading and coloured stone courses and master-classes throughout 2010 in Hatton Garden. Participants can learn about, book a place and pay for our own courses on-line through our website www.ericemms.com. Those who book a place on our January and/or February 2010 courses before the end of 2009 will receive a £10 cash-back discount, payable at the completion of the course.

Maintaining confidence in diamonds and gold

2009-11-04T19:22:00.002Z

John Hall, General Manager External Relations at Rio Tinto plc gave a talk on Consumer Confidence in the Jewellery Industry to the GIA London Alumni Association on 28^th October 2009.

John outlined a few of the current and past threats to consumer confidence in the jewellery industry, including the much debated topics of blood diamonds, the funding of terrorist groups by the sale of gems and of ‘dirty gold’. He presented evidence of how the consumer cares about the ethics of the supply chain and views on companies highlighted as being irresponsible on the ethic reputation.

John showed how other industries were adopting a certified ‘fairtrade’ position with their goods, such as Fairtrade certified cotton, cocoa and coffee; and the Forest Stewardship Council label on timber. Within our industry Wal-Mart has created a sustainable jewellery value network; its ‘Love, Earth’ jewellery collection is backed by a traceable path from mine to retail.

Industry initiatives to respond to threats were outlined; the Diamond Development Initiative considers the welfare of African artisanal miners in countries recovering from war and the Responsible Jewellery Council aims to develop a standard to cover each member of the diamond and gold supply chain. The standard, much like an ISO standard, will work by each member being verified by an accredited auditor before a certificate decision to certify the member is made. The process, the RJC system, is covered by a code of practices.

In conclusion, John emphasised the issues which are reframing the debate on consumer confidence;

efforts to make jewellery the first choice for consumer purchase despite attractive alternatives,
what is the differentiation proposition that will direct consumers to purchase jewellery as their first choice?
and how to create a whole jewellery industry-wide standard.

Comments on my recent Loughborough blogs

2009-10-03T16:36:00.001+01:00

Comments on these blogs have been posted on my Facebook page. http://www.facebook.com/eric.emms?ref=name

Loughborough 2009 (Part Four)

2009-10-02T10:49:00.000+01:00

In the third workshop, Tracy Jukes (having a busy conference) divided it into three portions; the first part involved attendees examining a variety of treated coloured stones and synthetic stones; the second part concentrated on gem prices and the third part involved assessing the quality and value of over 30 gems.

For the final main presentation, David Thomas, the latest but one Crown Jeweller, regaled his audience with stories of his time in office serving Buckingham Palace. He joined the jewellers, Collingswood & Co. at seventeen, starting on the wage of three pounds, 10 shillings a week. He stayed for 28 years, moving to Garrard in 1986. At Garrard he trained for five years with the then Crown Jeweller, Bill Summers, until taking over in the role in 1991. Thomas recounted many interesting stories about handling the Imperial State Crown in preparation for the annual State Opening of Parliament, looking after the Queen Mother’s Crown set with the Koh-i-Noor diamond during the lying-in-state of the Queen Mother in Westminster in 2002, making inventory of the Queen Mother’s jewels following her death, and attending to the jewels of the Norwegian Royal family. Thomas retired as Crown Jeweller in 2007 and left Garrard in January 2009. Illustrated with many pictures of individual jewels, the talk was very informative and amusing: the highlight for me of the conference.

During the final workshop I attended, Barbara Leal, another busy person during the conference, demonstrated the practicalities of grading colour in gems. She spoke of the ‘warm’ colours red, orange and yellow and the ‘cool’ colours green and blue, showed the colour wheel and described the grades of clarity and cut. We were given various gems and asked to grade for colour, clarity and cut.

Loughborough 2009 (Part Three)

2009-09-30T15:12:00.001+01:00

In her second presentation Tracey Jukes spoke on Market Trends in Coloured Stones. She said in a time of gem value volatility, price trends are increasing. In sapphires there has been a 50% increase in stones over one carat in the last year. Madagascan pink sapphire, discovered in the 1990s, following a price rise has dropped to a quarter of Sri Lankan stones. In rubies there has been a 100% premium for Mogok, Burma goods and Winza, Tanzania goods being expensive. In emeralds following the sharp drop in prices in the late 1990s owing to media coverage of fissure filling with resin materials, prices have recovered: 2008 prices of fine material were 4/5^th of peak prices. In Brazil only the Nova Era mine is in production. Tracy pointed out that prices were rising on pink spinel, pink topaz, brown and blue zircon, tanzanite and aquamarines(but not in large sizes of these two gems), alexandrites and fine sapphires. Prices have fallen for Paraiba-type tourmalines, pink sapphires and demantoid garnet. She said treatments, the US ban on the importation of Burmese stones, availability couples with supply in producer countries and demand in consumer societies, and foreign exchange rates have affected gem prices. In conclusion, Tracy mentioned internet sales, the increasing prices of man-made stones, gem treatments, the ethics of treatment disclose, responsible trade practises and the standardisation of gem certification will be future issues to be addressed.

In the second workshop I attended Brian Dunn spoke on gem price guides. He summarised current published diamond lists in use by Registered Valuers: NAG Price Guide, The Guide, Market Monitor and the Rapaport Diamond Price List. He emphasised the current volatility of diamond wholesale prices due to the recent financial recession and emerging recovery is making the assembling of prices by the different lists and the tracking of prices by users somewhat difficult. He gave a number of hypothetical diamond grades for the attendees to value using the different lists and comparison were made and differences noted. Brian advised more than one price list should be utilised to value a diamond and an average of values calculated. He demonstrated differences in lists prices were greater for larger diamonds. Turning to coloured stones Brian suggested the user of The Guide’s published ten quality grades should concentrate on the mid four grades 4,5,6 and 7, likely to be encountered. Examples of gems displaying the four quality grades were shown. Brian suggested the dollar per carat price shown in the Guide should be used as sterling per carat (except in the case of cultured pearls). In the

10% should be added to the guide values of emeralds

Loughborough 2009 (Part Two)

2009-09-30T08:42:00.000+01:00

The first workshop I attended, titled ‘A Practical Guide to Jadeite: Identification & Value”, was hosted by Rosamond Clayton, a Hatton Garden based jewellery valuer and acknowledged specialist in jadeite values. Attendees were given samples of jadeite imitations (e.g. serpentine, glass, Maw-Sit-Sit) and treatments (stained and polymer impregnated samples). Illustrations of imitations, antiques jadeites, the history of importation into China from Burma, the so-called 83-Jade (the low quality material treated to produced B-Jade (acid soaked and polymer impregnated) and the A-, B-, B+C, and C-jade were shown. Finally we were asked to assign values to various samples of natural, treated and imitation jadeites.

Barbara Leal, of the independent jewellery valuers, Jewellery Evaluations & Mediation Services, offered a main presentation on colour assessment of gems titled ‘Colour Speak’. Barbara spoke of how the colour of a gem is expressed sometimes in terms related to Nature, such as Cornflower blue (sapphires), Forest green and Pigeon’s Blood red (ruby) and illustrated the impression of these terms. She emphasised the value of a coloured gem is determined chiefly by its colour (she quoted colour as 70% of value, clarity 15% and shape and cutting precision as 15%) and reviewed the Munsell colour communication system utilising the colour “co-ordinates” of hue, tone and saturation forming a three-dimensional arrangement of colour and how this system has been adapted to describe and communicate the colour of gems. There are seven principle hues or colours; red, orange, yellow, green, blue, violet and purple and 24 modified colours, such as red-orange and yellowish green, totally 31 hues, forming the first dimension of hue. As an example a garnet may be orange but have a modifying red colour, being reddish orange.

The second co-ordinate, tone, is the lightness to darkness of a colour, graduated to nine numerical values, with greys between the extremes of white (0) and black (10). The tone of most gems would be judged between 2 and 8. As an example the tone of our orange garnet may be described as medium light (4).

The third co-ordinate is the dull to vivid purity of colour called saturation. The dull saturation of red, orange and yellow gems (warm colours) will display brownish purity whereas greyish dullness will be observed in the cool colours of green and blue gems, The extent of saturation is graduated from 1 to 6, vivid being 6. For example an orange garnet may be judged to have a very slightly brownish (3) saturation

The colour of gem judged to possess a hue of reddish orange (rO), having a medium light tone (4) and a very slightly brownish saturation (3) can be expressed as ‘medium light, very slightly, reddish orange’ or as ‘rO 4/3’.

Loughborough 2009 (Part One)

2009-09-29T15:05:00.000+01:00

This year’s Institute of Registered Valuers’ Conference was again held at Loughborough University, on Sat 19^th to Monday 21^st September. The conference’s major aim is to act as venue where jewellery valuers and others (including gemmologists such as me) can meet, attend informative lectures and workshops and discuss matters of mutual concern. Although the theme of this year’s meeting was the assessment of colour qualities and values of coloured stones, the conference was divided into two: main presentations where all participants can attend, and a number of workshops, such as antique jewellery, jadeite, and precious stone price lists, coloured stone grading methods, Chinese wristwatches and valuation processes. Naturally I chose workshops relevant to precious gems.

In the first main presentation Tracy Jukes of the coloured stone dealers, e-Jewel, summarised the current gem scene. She reviewed her trip to Tucson 2009, while noting a 40% drop in business at the shows, she emphasised the show is still worth attending for gem pricing information and noting the extent of stones on sale. More synthetic gems, simulants and coated stones were noticeable with Chinese vendors selling very cheap jewellery. She thought the shows were now more of a retail event where one can only buy on cash terms with US dollars. In the Gem District of Bangkok, Thailand, she saw an 80% drop in business, although gem prices have increased. Tracy illustrated the forms of gem treatments associated with heat. She showed slides of surface diffused corundum, bulk diffused examples, trading at 70% discount, glass-filling with a borosilicate ‘flux’, and lead-glass filling of gems where 20% of the gem’s weight could be the glass filler. She summarised one US gem laboratory’s description of the treatment at made reference to CIBJO’s ruby and sapphire guides. She briefly dealt with the current issue of emerald treatments, synthetic gems, simulants and coated stones. The importance of correct gem description (pink sapphire vs. ruby, and green beryl vs. aquamarine) and the definition of Paraiba tourmaline were briefly reviewed. The latest gem localities were summarised: sources of Tanzanian zircon, spinel, emerald and chrysoberyl; Nigerian tourmaline, Namibian demantoid garnet, Zambian pink and yellow tourmalines, Tanzanian rubies from Songea and Winza, Mozambique rubies and Madagascan sapphires were discussed. Tracy spoke of an 80% drop in Tanzanite production in the last 12 months, and finally fire quartz and sunstone, similar in appearance, were illustrated.

Gems at IJL 2009

2009-09-17T13:29:00.001+01:00

I consider the International Jewellery London the most important UK trade fair to attend. This year I was at the four-day event at Earls Court on Days 2 and 4 to see the range of gems on offer and to talk to past, present and potential clients.

On arrival I noticed an apparent drop in the number of exhibitors; vacant tables and chairs filled a number of gaps usually occupied by stands and, particularly on the last day, I felt there were fewer visitors in the aisles and at the seminars than in recent years. This was all to be expected in the present economic conditions. Those exhibitors I spoke to thought the first two days were more satisfactory (for sales) than the last two.

I did not bother researching diamond sales at the fair as I was there to look at coloured stones. I studied what was on offer from the dealers in the Gem Plaza, including Apsara Gems, G F Williams, Joias, Marcus McCallum and other exhibitors. But as I walked around IJL I was a little disheartened about greater number of potential buyers scrutinising the large array of strings of coloured stone beads on display while the fine rubies from Winza and attractive sapphires from Madagascar and Sri Lanka were passed by. However those who did peruse individual loose faceted stones were buying sapphires and rubies and I was delighted to hear the price premium asked by sellers for unheated corundum is now generally accepted by trade buyers.

Answer to the Summer Quiz

2009-09-10T18:09:00.005+01:00

The answer to my Summer competition is on my website.

The idea for the quiz came to me when I noticed this blue plaque as I was walking home in Marylebone. OK, I admit the links are tenuous but some of you had fun... One respondant thought the famous diamond featured in one of the plots of the soap (think of the blue diamond in the plot of the Titanic film). No, not to the best of my knowledge!

More on the Cullinan Blue diamond

2009-08-05T13:59:00.001+01:00

In an earlier blog entry, dated 15^th May, I described the blue diamond following my brief examination of it at Sotheby’s prior to its sale at auction. The diamond was sold in Geneva on 12^th May to a Hong Kong property tycoon and collector for US$9,488,754 or US$1,349,752 per carat, a world record for the highest value per carat for any gem sold at auction. The owner has christened the gem the ‘Star of Josephine’.

The diamond was cut in South Africa by Monnickendam Diamonds, a London based diamond merchant and cutter. On Tues 4^th August, a director of the firm presented a short illustrated talk relating the thoughts of the cutters as they considered fashioning the flawless gem from the 26.58 carat rough.

Petra Diamonds, the owner of the Cullinan mine in South Africa where the rough was recovered in 2008 approached Monnickendam to cut the gem. The two master cutters, Alan Hooke and Clive King with a company director spent three months in South Africa studying the rough and designing and cutting the gem.

On 2^nd February 2009 the cutters had their first sight of the rough. Immediately apparent was a large cleavage surface covered with larges fractures (‘gletzes’) and impact damages attributed to the recovery method.

For a fortnight the rough was studied using advanced rough diamond mapping and inclusion scanning software and a decision made to separate the rough using laser sawing into two parts. Positioning the saw line is always a compromise between potential maximum weight yield and potential maximum gem quality. The rough was sawn on the 17^th February, producing a smaller piece weighing 11.42 ct retaining the large gletzes and a larger portion, of 14.74 ct, having the possibility of being polished to a gem of fine clarity.

The smaller piece was worked upon subsequently to produce four faceted stones; two pear brilliants weighing 1.70ct and 1.03ct and two triangular stones weighing 0.46ct and 0.49ct.

The larger, finer, sawn portion was polished down from 14.74ct in order to explore a worrying gletz at its end. Only by working the stone to 12.65ct was the gletz considered ‘stable and not running’ and finally under control. The main facets were ‘blocked’ with an irregular hexagonal table facet taking shape as the stone was reduced to 11.14ct. Further cutting suggested a cushion-shaped outline: the stone now weighed less than ten carats at 9.48ct. Many minor gletzes were eliminated through further working to 8.17ct but a large hole at the bottom surface was now apparent.

By this time the cutting team were working intense eight-hour days as the pressure to fashion an exceptional stone grew. The final cushion shape modified brilliant cutting style was decided as the stone, still in its ‘blocked’ state, was polished to 8.03ct. But a gletz under the girdle became perceptible, requiring a complete reshaping of the cushion outline if a flawless diamond was to be attained.

At 7.26ct the gem had been faceted but the surface hole and associated gletzes were still apparent. Intense pressure was on to maintain a seven carater. At long last the diamond cutting was completed, attaining a flawless, fancy vivid blue diamond weighing 7.03ct.

The above note is my personal record of the talk as given on the 4^th.

A fun quiz for Summer.

2009-08-03T15:43:00.003+01:00

Answer the following question.

What is the connection between the Hope diamond
http://www.si.edu/Encyclopedia_Si/nmnh/hope.htm
and 'The Archers', the BBC long running radio soap?
http://www.bbc.co.uk/radio4/archers/

I will provide the answer in September!

'Emms Gems' Article Archive

2009-07-14T19:15:00.009+01:00

In the last few days several people have been complimentary about my series of gem articles 'Emms Gems' I wrote in the 1990s and published in the UK jewellery trade publication 'Retail Jeweller'. They have requested where they can find these articles. I have a few printed copies from that time and have added them to my 'Articles' page of my website at http://www.ericemms.com
If any of my readers have other printed editions of 'Emms Gems' I would be delighted to receive copies.

Reuters diamond video

2009-06-19T16:38:00.002+01:00

During Coutts London Jewellery Week, I was interviewed by Reuters for their item on diamonds. Although I was asked to discuss the quality, beauty and value of diamond, Reuters chose to emphasise the investment appeal of the gem. You can see the video by clicking on the title above.

June 09

2009-05-16T19:53:00.001+01:00

In June there is no let up with our courses and seminars. The NAG hosts our two day diamond grading course in the first week, our three day Exploring Gemstone course continues and our leading diamond grading course is held on the first week-end. We are presenting a seminar on diamond beauty during Coutts Jewellery Week, travel to Leeds to present another bespoke practical diamond course for jewellers and commence another Exploring Gemstones course in Hatton Garden. Please see our calendar page for details.

The Cullinan Blue Diamond

2009-05-15T18:05:00.001+01:00

I had the chance recently to view the blue diamond in London prior to its sale in Geneva.

For auction viewing purposes the 7.03 carat gem is mounted plainly and, one has to mention, not perfectly in a white metal ring.
The colour of the diamond is extremely attractive – a deep steely blue, evenly distributed over the crown when seen normal to the table facet. There is a just a hint of faint grey but one expects (and I wish) to see a little grey in blue diamonds. It’s what they are. I have only examined one diamond of fine sapphire coloration. The colour saturation does warrant the “Vivid” given by GIA and no mention of “grey” on their Report, quite rightly in my opinion.
The shape is a cushion with an appealing 1.05:1 length-to-width ratio and what is striking under the loupe is the facet arrangement. The table facet is an irregular hexagon in shape, (having a fold-fold symmetry and not six-fold). It is surrounded by six star, six kite and a dozen upper girdle facets (the irregular table shape necessitates the shapes of like crown facets to be incongruent. The pavilion is of a mixed style with four pavilion facets, pointing to the corners, being employed to maximise brilliancy and colour. One could question the perfection of the pavilion however I dare say the ‘model’ was decided to maintain the seven carat weight. I would describe the shape and cutting style of the gem as a “cushion modified brilliant”. Odd then, that the GIA on its grading report states the gem to be a “modified rectangular brilliant”. The perfection of the polishing appears to be high so I am surprised the gem’s GIA polish grade did not achieve ‘Excellent’ status.
The girdle is faceted and pretty thick in places, thick enough to take an inscription, perhaps in future a five letter word beginning with the letter G!
No parallel ‘grain’ lines were seen when briefly examined with a loupe. GIA has given an internally flawless grade; only an extra facet at one corner on the pavilion was noted. I was not able to ‘fluoresce’ the gem: the fluorescence is reported by GIA as ‘none’, the norm for blue diamonds.

Where it was found
The Cullinan mine was called the Premier mine until 2003 and is well-known as the source mine of the largest diamond crystal ever found. The 3,106 carat Cullinan diamond that yielded the 530 carat Great Star of Africa and the 317 carat Lesser Star of Africa, both in the Crown Jewels, was discovered in the mine in 1905 three years after it was established.
The mine has a reputation for yielding large rough of exceptional quality. Petra Diamonds, the mining group which bought the mine from De Beers in 2007, claims the mine has produced over 300 crystals weighing more than 100 carats, a quarter of stones weighing more than 400 carats and is the only significant source of fancy blue diamonds. Other famous diamonds recovered from the mine include the Centenary, the Golden Jubilee and the Taylor-Burton.
Rumour has it that the Cullinan Blue (a temporary name until the successful bidder at auction wins the honour of giving it a permanent name) was discovered in the tailings of the Cullinan mine! One wonders if this rumour is true!

Guest Blog - Hong Kong Fair: March 09

2009-05-02T14:15:00.003+01:00

Recently I asked how others had had experience of recent gem shows. In this first guest blog Peter Groenenboom, a gemmologist from the Netherlands shares his personal view of the Hong Kong Fair in March.

"All the four days I was at the show it was clear that there were at least a 35 to 40 % less visitors, mainly Westerners had not come. Later I heard that most Americans had not come, there were some booths of American dealers which were empty, the dealers had stayed at home. Specially the diamond sector was hit. Every time I had to walk through that area there were hardly any visitors, in the booths I saw no clients or any activity and often you saw the dealers talking with each other. Most of the dealers there are the Indians and Belgians. From Antwerp I heard that indeed the dealers had a very bad time in HK.
A friend of mine who is dealing in coloured diamonds in HK, which are/were very popular with the HK rich, have dropped in price. Sometimes 25 to 35 %. But good stones above 1 ct. are stable in price.
It’s the same with coloured stones. Natural untreated ones are even more expensive than last year, and harder to get. I have seen reddish spinel, 4-5 ct good cut, for 5000 USD/ct. I wonder if you want to buy that stone if you have to pay that price, probably not. But spinel, spessartine, nice untreated blue sapphires, to name a few, are certainly not cheap.

In the small sizes and treated stones you can buy what you want, there was plenty and to my feeling lower prices than last year. Dealers wanted to get rid of their stock.

In the pearl business it was more or less the same. One of my freshwater pearl suppliers is a big producer/dealer with a big booth. But this time it was not the frenzy action as I know this booth, people had time to talk, it was nice, there were some customers, you didn’t had to work to get attention. They were doing OK, but it was clear they had a significant lower turnover than usual. The very high quality I look for had become higher in price for the coloured round/semi round 9,5-10 mm (40 USD), 11-11,5 mm (60 USD) and 11,5-12 mm (70 USD).
(I have to say that with high quality I mean really high, most people, even long time pearl dealers, have not seen this quality. They have a strong colour and a high or metallic lustre. They are the pearls Schoeffel uses in its high end jewellery, if you know that. I buy and sell those pearls loose.).
For 12 to 13 mm they asked 180 USD, I didn’t buy that. I offered 125 USD but they didn’t want to come down one dollar. That suprised me. And I’m a long time buyer from them.
White beaded pearls had become much cheaper. Most of those are baroque, but there were nice pearls in those lots, prices about 40-50 USD/piece. I didn’t buy those. Also I did not look for round white pearls.
Strands of good quality lavender, copper colour or with metallic lustre were not available or high in price : 9-10 mm 300-400 USD. Too high for me. Same with round and baroque white pearls. Multi-coloured strands of reasonable quality were plenty for lower prices, 8-9 mm 100 USD, used to be 150 USD.
One of my suppliers, who has many American clients and is dealing in high quality white freshwater strands had hardly any sales. They were not crying, but it looked close to that.
Everything in the lower and medium qualities were lower in price. Also here I had the feeling that dealers wanted to sell for any price.
Tahiti pearls above 12 mm are hard to get since August last year. My ‘Tahiti’ dealer don’t have good/high quality 12 mm round because they refused to pay the high prices the producers (=Robert Wan) asked. Also on the last auctions there were none or very few big pearls. The ones that were on auction went for very high prices.
I was lucky that three of my suppliers each had some nice Tahiti’s of 12 to 15 mm which I bought for last years prices. But I saw some of the big dealers (Tasaki, London Pearls) with really very nice Tahiti’s of 14 and 15 mm, but asking price 800-1000 USD !! That is really too much! But try to get that kind of pearls, that’s hard.
But everything below 12 mm was in abundance. 10 mm about 60-90 USD, depending on the quality. Same story for high quality South Sea cultured pearls. Above 12 mm very high prices.
My suppliers were very satisfied with the show, they had covered all their expenses! Which means that most dealers lost.

Some dealers (stones or pearls) told me that they were not going to the Basel Fair. What I have heard is that the Fair was bad. But this you better ask others who were there.

Also I heard from the dealers in HK that the Bangkok Fair was very bad, about 50 % less visitors it seems. I know of one dealer in Bangkok of which business had come nearly to a stand still. That seems to be the common situation.

At the GIT Conference (where were you ?) there were also not too many people, if you ask me. Plenty Westerners, but besides a few losers like me who had to pay for the attendance, all were speakers. And from the handful paying Westerners at least three or more were living in Bangkok.
By the way, a very good conference, the Thais are doing very well, gemmological speaking.

The hotel in Hong Kong as the one in Bangkok, both 3*, made the situation also clear : In all the years I come there at breakfast the restaurant is filled for at least a third, say 10-15 people. Now I was the only one or there were 2-4 other guests.
It seems that Thailand has about 50% less tourists now, a big problem for many people.

This report has become larger than I planned, I hope it has some info you can use."

Gems in Greenwich

2009-04-27T14:47:00.002+01:00

I like visiting Greenwich, on the river in south-east London. Its maritime and scientific heritage permeates the air and is immediately detectable when one alights from the London commuter train. The grand buildings of the Queen’s House, Greenwich Hospital and the Royal Observatory, all within walking distance of the station, are the finest examples of the English interpretation of Baroque architecture.

Not quite of that epoch is the modern hotel venue of my latest one-day diamond grading course arranged by the NPA for pawnbrokers. A dozen attendees from Eastern England learnt more of diamond identification, particularly how the loupe, when utilised correctly with a sceptical and enquiring mind, is a more powerful aid than a so-called ‘diamond tester’.

Judging quality and size of diamonds were considered with emphasis on the benefits of using a millimetre gauge to estimate carat size as a superior means than the ‘hole gauge’plates still made use of by many pawnbrokers. One of the intentions of these short workshops is to demonstrate to pawnbrokers that there is more to establishing diamond values than guessing stone weights.

Fluorescence in Diamonds

2009-04-18T16:29:00.001+01:00

An established client stops me in the Garden to enquire of my diamond courses. “Please tell your students that fluorescence is not a bad thing” he implores me. I agree. It seems the diamond industry considers fluorescence, the glow seen when gems are bathed in ultra-violet light, as a negative attribute and many will not trade a fluorescent diamond.
Which is a pity as a soft blue glow may lift the appearance of an off-colour stone.
I suspect many in the diamond industry do not know what causes the phenomenon and cannot explain it to consumers. The undesirability of fluorescent diamonds is reinforced by published prices for such diamonds at discounted levels to non-fluorescent stones.
But explained in positive terms I believe fluorescence can be made into an appealing element of diamond.

The new 4Cs

2009-04-15T15:30:00.002+01:00

We all know the 4cs of diamond quality: Carat weight, Colour, Clarity and Cut but I’ve just read of another mnemonic set. In an article printed in the latest addition of The Jeweller, a UK trade journal published by the National Association of Goldsmiths (the trade association for retail jewellers) there is some timely suggestions on how enterprises should be thinking about when planning to respond to the problems posed by the developing recession.

The ‘new’ four Cs are Cash, Customers, Costs and Confidence. Nothing original in the article about conserving ready money, exceeding the needs of consumers and controlling overheads but a useful summary ending with the call to celebrate any positive developments in ones business. Today these new 4Cs should be addressed in our daily ‘to do’ lists.

Gems at Trade Shows in 2009

2009-04-01T15:45:00.000+01:00

Some information please from readers who have attended trade shows in 2009. From your experience at the shows what information did you receive on diamonds and coloured stones? I am interested in sizes, colours etc selling, prices fetched and main trends. I read items from Rapaport, Idexonline, PolishedPrices, ICA etc regarding gem news for trade shows however I wish to learn from those you attended the shows and wish to post their observations here.
Thanks.

April - hopefully not "the cruellest month" in 2009

2009-03-20T16:15:00.005Z

Diamond is the birthstone for April and in April we continue our short diamond courses offer.
A two day bespoke course for a retailer in Leeds, a two-day Diamonds and Diamond Grading course in Bury organised by the National Pawnbrokers' Association, a one day Diamond Course for pawnbrokers in Cambridge, our monthly week-end Practical Diamond Grading course in Hatton Garden organised by Holts Academy and the first two-day midweek diamonds and diamond grading course organised by the National Association of Goldsmiths will be held. Please see our calendar page for details.

Perth, Scotland

2009-03-20T15:51:00.001Z

The latest one day course provided by the National Association of Pawnbrokers saw me present on 12th March in the agreeable Scottish town of Perth. A six hour, 400 mile train journey on the Highland Chieftain from King’s Cross the prior day took me to the town on the River Tay and key transport hub for rail and road journeys throughout in Scotland in good time for dinner and rest. Eleven pawnbrokers journeyed to the hotel venue from six Scottish cities to learn more on diamonds. We considered more certain methods of identifying diamonds than the use of hand-held diamond “testers”, in particular using the jewellers’ 10x lens to note the sharp edges of diamonds’ facet edges, the characteristic appearance of inclusions and the girdle edge, and the distinctive lustre and dispersion of the gem when compared with simulants such as moissanite and cubic zirconia. Delegates learnt more on examining the number, sizes, position within the gem and the nature of inclusions to determine the diamond clarity grade. Laser-drilled and fracture-filled diamonds were scrutinised and quick methods to identify these treatments were discussed.

Pawnbroking

2009-03-10T09:33:00.000Z

Pawnbrokers are weathering well the present economic storm. They provide loans to the public, many of whom have a restricted access to, or are excluded from borrowing fromm high street banks. Most loans are secured or pledged against gold and diamond set jewellery. Clearly there is a need for pawnbrokers to correctly identify and calculate the value of any diamonds pledged in order to offer an acceptable amount of loan.

In the past the size of the diamond was the dominant factor determining loan size. Today pawnbrokers wish to learn more of diamond quality: the colour, clarity and cutting perfection of diamonds. In addition many pawnbrokers sell second-hand jewellery; a greater knowledge of diamond identity and quality makes pawnbrokers better retailers. In last months I have been presenting short courses organised by the National Association of Pawnbrokers in order for pawnbrokers to become more skilled at handling diamonds.

My latest two-day diamond course for pawnbrokers was held in Sutton, Surrey. Established pawnbrokers and those wishing to enter the business examined diamonds, cubic zirconia, moissanites, laser-drilled diamonds and fracture-filled diamonds and experienced the range of diamond colours, clarities and cut grades from the finest, through to the commercial qualities, to, let’s called it, the lower “mixed” qualities.

The next two-day diamond course designed for pawnbrokers is in Bury, Lancashire on 21st and 22nd April. Soon after on the 28th and 29th April is my next two-day diamond course for retailers in Central London.

Grading In Birmingham

2009-03-02T13:49:00.001Z

To Birmingham city centre to present my latest course on diamonds. These one-day training sessions on diamond identity and quality are being held in various cities throughout the UK.

There is something about this city centre that depresses me. It’s the appalling collection of ugly post 1960s buildings scattered in the centre without any apparent coherent plan. On my way to the course venue I was frustrated in negotiating one particular eye-sore enchantingly named ‘Paradise Circus’! The absolute visual brutality of this quarter must surely affect the mental well-being of all who toil here.

My spirits were lifted by the application and enthusiasm of all who attended my diamond course. A dozen had travelled from cities and towns in Mid-England to learn more of identifying diamonds and diamond treatments, and of judging the clarity, colour, weight and perfection of cut. I continue to be agreeably surprised by the volume of knowledge absorbed by the attendees during the short course.

Our next visit is to Scotland. To Perth – a prettier city.

Hoards of Jewels

2009-02-25T09:47:00.002Z

Walking home from Bond Street, I pass my ‘local’ museum, the excellent Wallace Collection, where my eyes are attracted to their wall poster “Treasures of the Black Death – amazing unseen jewels”.

Intrigued, I pop down to their basement exhibition to view these gem-set pieces. Here, on display for the first time in London, are two hoards of 13th and 14th century silver and gold jewels unearthed in France and Germany. Both hoards were buried, it’s believed, by Jewish merchants fleeing their communities in mid Europe at the time of the Black Death in the mid 14th century.

Silver coins and silver vessels are showcased but what attracted my gemmological eyes were the gem-set brooches particularly the simple symmetry of a ruby, sapphire and pearl brooch. The central octagonal ruby is faceted whereas the other gems are cabochons, all in rub-over, backed (possibly painted) settings (‘pie-crust’ according to the literature). The tiny baroque pearls, European river pearls I assume, are fully drilled in the mount. All gems stand proud, are quite small so difficult to study, even with the ‘granny lenses’ supplied.

It is surprising to realise the eye-catching jewel was made in the second quarter of the 14th century and to contemplate the wide-spread trade in gems at that time which made its construction possible.

Well worth jewellery markers/designers and gemmologists attending this exhibition before it closes in mid May.

Mad March haring around

2009-02-14T17:10:00.000Z

In March I am offering a two-day Diamonds and Diamond Grading course in Sutton organised by the National Pawnbrokers' Association, a one day Diamond Course for pawnbrokers in Perth, a week-end Practical Diamond Grading course in Hatton Garden organised by Holts Academy, our third bespoke two-day Diamond Grading Course for a retailer in Altrincham, a three-day Exploring Gemstones course in Hatton Garden organised by Holts Academy and a one day Diamond Course for pawnbrokers in Greenwich.

Gems in Hebden Bridge

2009-02-04T10:35:00.009Z

The snow-fall crippling London and much of England on Mon 2nd Feb failed to prevent me travelling to and presenting my latest corporate gem training session on behalf of Holts Academy. Well situated in the pleasant Pennine town of Hebden Bridge in West Yorkshire, Element contemporary jewellers had invited me to offer a two day session on gem understanding. Such is the owners’ commitment to maximising staff awareness of precious stones that the showroom was closed to the public for the two days to allow all five staff to participate.

Day One was devoted to diamonds. We looked first at different qualities of clarity and colour in diamonds currently sold in UK retail jewellers then moved onto identifying diamond, being confident in distinguishing diamond from its simulants CZ and moissanite. The methods by which gem diamonds are treated to alter clarity and colour were practised and the optical properties and characteristics of cut which make for a diamond of maximum brilliance were discussed. A review of diamond weight was followed by the benefits of diamond certification, with emphasis on the GIA dossier, were considered. Finally fancy coloured diamonds and synthetic gem quality diamonds were looked at.

Coloured stones were the topic of Day Two. An overview of the popular (and rarer) gem varieties available was given with emphasis on the major gem group names and consideration given to simulants and synthetic counterparts. The extent of gem treatments was emphasised and the proper description and disclosure of treatments to the public were debated. Next the marvellous wide range of colour existing within the gem species was demonstrated with examples seen. Quality factors were considered and problems of colour description and communication were discussed. We looked at the proper handling and care of precious stone jewellery and finished the day with a debate on the ethical and social responsibility issues of the jewellery industry – a topic the owners and staff of Element feel particularly passion about and is evident in their day-to-day business activities.

Information on Element contemporary jewellers can be found here.

In The Vault

2009-01-31T14:22:00.002Z

For the culmination of my three day Exploring Gemstones course run in association with Holts Academy I took my gem students to the Natural History Museum in South Kensington to view the gems on display in The Vault. Being my first visit to this relatively new instillation I was keen to observe how the exhibit was arranged in order to ignite and develop the public’s enthralment with precious stones.
The Vault is at the end of the long mineral gallery. The latter still populated with rows of dark Victorian display cases occupied by diverse grey minerals arranged by their chemical composition- all very comprehensive I’m sure but not my cup of tea. In the Vault there were not many other visitors but it was a dull January mid-week afternoon but what a revelation.
First to attract my eye is the Star of South Africa – a truly historical diamond I spied last, I believe, in 2001 at the Paris diamond exhibition. Pear-shaped and weighing 47.69 carats, it’s displayed on its pendant attachment. Unfortunately the lighting in the show-case did not illuminate the gem’s beauty to best advantage. However that was superior to the total lack of light within the show-case labelled to be holding alexandrite. I could not detect whether it was a rough or polished specimen! My appeal for some light to the attendant security employee fell on deaf ears.
Next to be admired was the Devonshire emerald – a rough crystal of outstanding colour. Over 1,300 carats from Muzo; if you wish to see what the finest green an emerald can display go take a look at the crystal. It was my first view: it is simply stunning. In adjacent show-cases were superb examples of rough and polished gems with I thought more emphasis placed on the former. The lighting again was disappointing leaving the faceted Burma rubies slightly in shadow.
After admiring the fluorescent display of the Aurora collection of fancy coloured diamonds, one regains the mineral room. I looked to ensure a superb ‘sleeper’ gem I spotted years ago still remains neglected and little noticed among the gloominess of the silicate minerals.

Exploring Gemstones

2009-01-30T17:50:00.000Z

First Exploring Gemstones course of 2009.
My three day introduction to coloured stones held in Hatton Garden 19th to 21st January drew a diverse cohort of learners: from a would-be Brazilian gem dealer to a French GP doctor. All learnt more of the broad array of colours existing in gems, the range of hues seen in particular gem species and the criteria of gem quality. Basic use of gem testing instruments to identify species and treatments was practised. The course concluded with a visit to the fine quality gems on display in The Vault at the Natural History Museum.

"Collections" 2009

2009-01-25T16:08:00.002Z

Sunday 18th January 2009.
Off to Earl’s Court One exhibition hall for the first jewellery fair of the year; “Collections”. Billed as ‘the premier Spring Jewellery show of the year’ it is the second year showing of emerging young designers exhibiting their precious and ‘non-precious’ jewellery. It was my first visit. Arriving on the first floor of the hall I was greeting with heat and dimness. After negotiating the illogical stand numbering, I found my way around, conversing with past students and attempting to promote the use of precious stones in the designers’ work: diamonds and coloured stones were rarely seen in the jewellery on display. Judging by the numbers enrolling on my short courses, current and prospective jewellery designer makers are seeking knowledge of gems. Let’s hope in the near future this awareness translates into a manifestation of gem-set jewellery.

2009 and all that...

2009-01-16T15:19:00.003Z

I return to Hatton Garden from my Christmas and New Year break to encounter the depressing news and data of our industry. The not unexpected poor holiday sales figures from Signet and the steep decline in the number of gold items submitted to UK assay offices in the last quarter of '08 are just two published evidence of the UK gem and jewellery industry facing a grim 2009. Job redundancies at GIA in the US and planned reduction of jobs at Signet headquarters, the Diamond Trading Company and at Christies are the first publicized examples of gem positions being eliminated in 2009 – we shall surely see more jobs lost in the coming months.
On a more positive note, I was pleased my first training event was a new experience for me: a ‘One-to-One’ gem session with a jewellery designer – a day of demonstrating and discussing the range of colours in gemstones, the wide spread of gem varieties available for use, the attributes of a gem needed to exhibit beauty, simple tips for gem identification and the correct methods of caring for, and describing gems to the prospective purchaser. I hope to offer more such mentoring days throughout the year.
As I walk to the tube station I pass a sign outside the Mitre pub in Hatton Garden declaring “Things Will Be Fine in 2009”.

Diamonds and cultures

2008-12-11T10:39:00.004Z

Sat. 6th December.
For the last Week-end Practical Diamond Grading Course of 2008, I trained a group of young learners wishing to know more on diamond quality, beauty and identity.
An absorbing understanding for all of us to discover what the emotions provoked by diamonds signify to those drawn from the heritages of England, Ireland, France, Poland, Russia and Lebanon. It will be interesting to know how the learners exploit their new found knowledge of diamonds in their future careers.

A December Saturday in Hatton Garden

2008-12-10T10:35:00.002Z

In Hatton Garden on Saturday 6th December for the first day of my Week-end Practical Diamond Grading Course, the last one of 2008. Walking along the street I have trod for thirty years, I noticed the distinct lack of shoppers – very few looking in jewellers’ window displays. I realise jewellers become busier ever closer to the end of business on Christmas Eve and past trends suggest this burst of activity occurs ever more closer to Christmas Eve as each year goes by.

However I did expect more window shoppers in the Garden three Saturdays before the 25th, especially as this was the Saturday, according to retail sales analysts, when the public goes window shopping in their greatest numbers, gathering prices and information so they can shop online during their lunch breaks at work on the following Monday. This day is dubbed ‘Mega-Monday’, for this is the busiest day of the year for on-line sales. Preliminary results suggest £320 million of goods were sold online on Mon 8th Dec: the highest daily online sales on record. What fraction of this total was precious jewellery is unknown.

Obtaining retail sales for the total UK jewellery industry has been difficult for me to obtain. Little data is published by industry members or their trade associations. The Signet Group have a brief overview on their website but that’s about it. At a conference I attended this year, a speaker from Verdict Research, a UK retail research authority, said they use only data provided by the Government’s Office of National Statistics when examining trends in the UK jewellery market. This data looks to me quite sparse. Perhaps we can only gauge the performance of the UK gem and jewellery industry from anecdotal evidence of retailers. We shall hear more of this in the first few weeks of 2009.

Verdict Research predicts total UK retail spending on the ‘high street’ will decrease 4% next year, the greatest annual drop since their records began in 1965, indicating a loss of £3.6 bn from high street retailers’ profits. Of course on-line companies are stealing market share from ‘bricks&mortar’ shops as hard pressed consumers look at web comparison sites and a cheaper, more convenient way of buying. However the latest data suggest on-line sales growth is slowing and that boom may be now over.

Training pawnbrokers

2008-11-30T20:25:00.002Z

18th November.
To Bury in Lancashire to teach the latest two-day Practical Diamond Grading course for pawnbrokers hosted by the National Pawnbrokers’ Association. Bury is north-east of Manchester and evidence of Bury’s 19th century wealth derived from cotton is seen in the town’s Victorian architecture I find so appealing.
Pawnbrokers from the North West attended the course and studied identifying diamonds, determining diamond size and quality using simple hand held instruments. I will be teaching further courses for pawnbrokers next year in Sutton, Wolverhampton and again in Bury. Details from the National Pawnbrokers’ Association.

Round brilliant diamond design

2008-11-20T17:53:00.001Z

Wednesday 29th October: a day it snowed in London in October for the first time in 70 years saw me pitch up at GIA London campus to introduce the latest alumni group talk. Al Gilbertson, a research associate from GIA Carlsbad, gave a fascinating illustrated view of the evolution of the modern round brilliant cut diamond design. Gilbertson is one of the GIA staff who worked on producing the GIA grading system for the cut of a round brilliant diamond. His research led him to consider the early ideas for round diamond design originating in London and Boston, USA and he has explained the development of the design in his book ‘American Cut – The First 100 years’.

Gem-A 2008 Conference

2008-11-02T16:31:00.002Z

To Notting Hill on 25th and 26th October for the 2008 Gem-A Centenary Conference and 2nd European Gemmological Symposium for a week-end of networking with laboratory gemmologists, valuers and jewellers and to listen to presentations from international speakers on two gem themes. The first day concentrated on the Foundations of Gemmology which traced gem studies in ancient literature and practice, to the use of gems in historic jewellery such as eighteenth-century Portuguese jewellery and the Swedish Crown jewels to the development of the study of gemstone inclusions. The second day was devoted to Practical Gemmology in the Modern World, with presentations on the valuable use of portable gemmological instruments, a conjecture on what other ‘high-tech’ instruments will be needed in the near future, to the latest coloured gemstone discoveries in Canada and new data presented on how treated colour quartzes can be identified
One of the better gem conferences I have attended.

Learning About Coloured Gemstones

2008-11-02T15:50:00.001Z

Late October I presented my first short course on coloured stones to a group of gem enthusiasts.

At the Holts Academy in Hatton Garden I taught the three day ‘Exploring Gemstones’ practical course. Attendees handled and examined the broad range of coloured stones seen in today’s marketplace and were taught simple tips to help identify them.

The course concluded with a visit to the Holts lapidary workshop.

Christie's Pearl Evening

2008-10-27T14:10:00.001Z

Mon 29th September
To Christies in St James’s, London for an evening of natural pearls. First, the viewing of the natural pearls to be auctioned in Dubai on 29th October, exhibited together a very fine alexandrite and exceptional peridots. What excited the senses more than these beauties though was another opportunity to view the Hope pearl, Pearl of Asia and the Centaur Pearl; three exceptional pearls I have examined in the past.
Following three varied talks on natural pearls, the audience witnessed the unveiling of large pearl and asked to consider it to be the largest pearl purchased and illustrated by Tavernier in his book describing his 17th century travels to India.
2008 is the centenary of the publication of Kunz and Stevenson’s Book of the Pearl – still the supreme tome on the topic; appropriate then, that a copy was on view at the exhibition.

Diamond identification in 30 minutes

2008-09-27T16:08:00.002+01:00

Tues 23rd September. To the south bank of the Thames, next to City Hall, for my presentation to a group of City solicitors’ clients. My brief 30 minute chat was on the quality characteristics and how my audience could and would identify diamond from CZ using loupe and tweezers.

Each guest present received a colourless stone – all were CZ apart from one. Fun time was had as a spot of diamond identification by all followed. A lucky lady identified her stone as the sole diamond and took her prize home!

Loughborough 2008

2008-09-27T15:55:00.002+01:00

September 20th: To Loughborough for the annual NAG valuers’ and jewellers’ conference week-end. Perfect train journey this year following two previous years of appalling rail service. Gave two ninety-minute workshops over the week-end on the value (benefits and drawbacks) of diamond ‘certificates’. Other presenters spoke on being an ‘expert witness’, on valuing and testing coloured stones, Arts and Crafts silver, Andrew Grima, cameos, counterfeit watches, Masonic jewellery and other valuing skills.

Highlight for me was John Benjamin’s fine illustrated talk on Georgian jewellery: the low point for most attendees was the half hour wasted on the non-debate on internet and TV jewellery shopping channels.
Anyone interested in gems, jewellery and valuations should attend Loughborough on the third weekend of September.

Eric Emms and Gem-A

2008-09-11T19:10:00.002+01:00

I am delighted to announce my company's alliance with the Gemmological Association of Great Britain (Gem-A). Follow this link to read our press release.

Gem Quality Synthetic Diamonds

2008-07-18T18:02:00.005+01:00

Wed 9th July - to the latest specialist evening of the Gem-A Gem Club. This month an illustrated presentation on Synthetic Diamonds by Branko Deljanin of EGL Vancouver, Canada.
Branko has co-written a booklet on synthetic diamonds titled “Laboratory-Grown Diamonds, an Information Guide to HPHT-grown and CVD-grown Diamonds”.

Branko’s talk reviewed the processes for growing gem quality synthetic diamonds; the equipment used, current producers and processors, and methods employed by gemmologists to identify these products.

The current producers of High Pressure High Temperature (HPHT)-grown diamonds and diamonds grown by the chemical vapour deposition (CVD) process are Gemesis, Chatham, Apollo, AOTC and others. All of AOTC produced synthetic diamonds (approx 10,000 cts/a) are certified by EGL Canada and sold as Adia created diamonds. Most are less than 0.75ct, yellow of VS clarity.

Branko reminded his audience laboratory based gemmologists identify gem quality synthetic diamonds by looking for tell-tale characteristics in near infra-red (NIR) spectra, Fourier transform infra-red (FTIR) spectra, cathodoluminescence (CL) and photoluminescence (PL) and energy dispersive X-ray fluorescence (EDXRF) spectra.

Examination by DiamondView also helps.

When examining tiny synthetic diamonds, Branko found looking at the strain patterns revealed under cross polarised filters (CPF) and observing reactions to short-wave ultra-violet (SWUV) light aids in identification.

A brief consideration of certification of synthetic diamonds concluded the talk.

Branko’s book is available from Gem-A Instruments

Gem-A Centenary Dinner

2008-07-08T19:00:00.003+01:00

Thurs 3rd July, 7.00 pm to Goldsmiths’ Hall in the City of London for the Centenary Dinner of the Gemmological Association of Great Britain. Always pleased to be inside this historic building (history and images here), returning here many times to view jewellery exhibitions since my first visit when I was awarded my fellowship gem diploma in the late 1970s.
Delightful to see and talk to many familiar faces attending the dinner, many I haven’t seen for years, some travelling from the US and Far East to be present for the dinner.

After a glass (or two) of something cool and bubbly in the adjoining rooms, into the Livery Hall for the dinner and chance to gaze with admiration at the four matching chandeliers each lit both by electricity and 48 twinkling candles. Following Grace spoken inexplicably with a maritime theme I had the chance to converse and debate with old clients and new friends over crab, lamb and Bakewell tart (mis-spelt curiously as Blakewell on the menu!)
After dinner, in front of the Goldsmiths’ Company ceremonial plate and huge royal arms of William IV, John Benjamin, the independent jewellery consultant, spoke on how he started in the gem and jewellery trade and the wonder items he handles evokes in his emotions.

The Centenary Dinner marks the anniversary of the 1908 meeting of the directors of the National Association of Goldsmiths of Great Britain and Ireland (NAG) which established the first courses and examinations in gemmology. The Gemmological Association, now known for better or worse as Gem-A, was ‘spun’ out of the educational department of the NAG in the 1930s so this year does not exactly mark the centenary of Gem-A however it does make for a grand historical excuse for a enjoyable dinner. Not sure whether I shall be around the trade for the proper centenary!

Gem-A AGM

2008-07-08T18:44:00.004+01:00

Monday 30th June, 5.45pm: To the National Liberal Club in Whitehall, London for the Annual General Meeting of Gem-A.
Lovely Victorian building: on walls all glazed tiles and pictures of former grandees of the now largely irrelevant political party. Chance to say hello to a few gem chums before the short meeting to vote through the 2007 report and financial statements of Gem-A (available here). Only one dissenting voice of a member raised to draw attention to the current dire finances of the Association then on to a following talk by David Warren, Department Head of Jewellery at Christie's London and Dubai. In a refreshingly low-tech style: no power-point or slide illustrations, he spoke in an anecdotal manner of his 30 years experience of handling jewellery and clients at the auction house. David’s tales of the characters with whom he has met and of the historic gems he has handled entertained the small number of gemmologists present.

Hatton Garden Jewellery Week Day 7

2008-06-18T16:16:00.005+01:00

15th June
A Sunday but no day of rest: it’s the last day of London Jewellery Week.
To Langdales and breathe in the floral scent of the still bewooded training room. In morning I gave my ‘How to Buy Diamonds & Precious Stones’ presentation to a standing-room-only audience. More than the twenty anticipated and quite a few who had never been to Hatton Garden area before. All keen to learn more regarding gems; their beauty and rarity. Many will now enrol on gem courses in London.

Walk down the Garden on way to lunch past the spot where these chaps were learning ‘to buy diamonds & precious stones’ in 1929!

After lunch to the Tower of London – not been there for many a decade, to visit the Treasures at the Tower exhibition by thirty promising jewellery designers. Finally tracked down the venue within the Tower ground and quite a number of exhibitors and visitors are past students of mine or I had met as graduates of GIA-London and Gem-A. After conversing with them and examining the use of gems in their pieces and sampling some bubbly (well, Aussie pink fizz) off home.
Tomorrow the collation of names and contact details of those I spoke to during London Jewellery Week may begin but I think, now it’s finally over, I deserve a little rest.

Hatton Garden Jewellery Week Day 6

2008-06-16T15:40:00.007+01:00

Sat 14th June.
No rest for the gemmological. A spot of technological trouble loading my presentation on to a laptop forces me to hurry from the Garden to my home and return to Langdales in the space of forty frantic minutes. Present my seminar on Famous Gems – the stories behind the most notable precious stones, for Holts Academy but not in their training room presently bewooded but in a basement workshop which made for rather a cramped time. Extremely grateful to one attendee who corrected graciously my pronunciation of the words ‘Koh-i-Noor’ and ‘Mughul’.

Part of Hatton Garden towards Holborn Circus closed to traffic today for the first time I can remember: I make a point of walking deliberately along its length in the middle of the road as the pleasant street music continues.

7.30pm To Flaneaur restaurant to talk again on seven gems during the 7 Gems, 7 wines and 7 Taste evening. More diners this time made for a busy evening answering questions during the starter, main and pudding courses.

Another tiring but fun day.

Hatton Garden Jewellery Week Day 5

2008-06-16T14:50:00.001+01:00

Fri 13th May.
As a change to giving gem seminars and demonstrations during this London Jewellery Week, today is my chance to attend a few. Just before lunch I’m present at The Hatton (no, not a pub but a training and conference venue) for the first of two talks by Jack Ogden, CEO of the Gemmological Association, on ‘Treasure, Traditions and Tricksters: a history of gems’.
After lunch to Bond Street on business and then to Mappin & Webb in Regent Street to ask staff questions on the 100 facets of the Cento round modified diamond being marketed by Roberto Coin.
Then to GIA-London in Bloomsbury to talk to its Director, Edward Johnson, class instructors, present and future students and to listen to one of GIA class presentations.

Hatton Garden Jewellery Week Day 4

2008-06-16T14:20:00.004+01:00

Thurs 12th July
6pm to the crypt of St Etheldreda’s Church in Ely Place, next to Hatton Garden. The interesting history to this ancient site can be read here.

Invited to the Holts Academy of Jewellery Awards Ceremony to help celebrate the accomplishment and ability of their gem and jewellery students.
The evening started dramatically with a modern dance routine performed in the crypt by a troupe of bejewelled young ladies (I wondered what St Etheldreda’s priests of centuries past would have thought of this display), followed by the student award winners being presented with their prizes and viewing of the sudents' work.
After lingering to talk to past students and industry colleagues, old and new, I walked around the corner to attended a couple of receptions where, over glasses of something cool and bubbly, there was much talk of gem colour, jewel materials and form, metal engraving, web-site design and the future for jewellery designers.

Hatton Garden Jewellery Week Day 3

2008-06-12T15:38:00.004+01:00

Today, Wed 11th June is the start of Coutts London Jewellery Week.

Up early into Hatton Garden to help set up the Langdales training room for my three 2-hour demonstrations of diamond identification today for Holts Academy.

Arrived to find several birch trees in large pots placed in the room! Silk butterflies nestling on branches, calming bird-song on the audio, butterfly images projected onto the wall and a table laid for a tea-party. Obviously the girls from Garden Studios setting up for their week’s events. Managed to set up desks, chairs and grading lamps in time, ready for the first of my demonstrations

10 am - First fifteen attendees pitched up. All bemused to learn about diamonds among the birch trees! Short presentation by me on diamond identification, treatments, global distribution, demand and prices then trained them to hold loupe, tweezers and diamond, examine a diamond, compare it to CZ and moissanite, demonstrate to them the clarity characteristics and grade, point out the colour grade and cutting style. Then showed them some synthetic diamonds and discuss current topics of industry concern. All this in two hours while being filmed by a production company for television transmission on The Jewellery Channel.
12 noon Time for quick filmed interview on diamond identification while another film crew arrives to interview Academy staff.
Spot of quick lunch and coffee
1.30 pm Another two-hour demonstration for another 12 attendees followed without a break at 3.30 pm for another 15 attendees. Quite a few had never been to Hatton Garden before. I managed to emphasis the distinction between natural diamond, diamond simulants and synthetic diamonds - interesting to learn many attendees associated synthetic diamonds with crystallised dead people!
Very little time to rest after six hours on my feet until my evening talk on Seven Gems.

6.30 pm sees me pop round the corner to Flaneur restaurant and food hall at 41 Farringdon Road. Here, Nick McGill, the owner had arranged a seven course dinner menu of food to match the colour of seven gems and each course to be accompanied by a wine produced in a country of origin of each gem. To the assembled group of diners, sitting at a long table, at the start of each course, I gave a short talk on the seven gems, showing both rough material and faceted examples and Nick spoke of the food and each wine. The menu, and gems discussed can be viewed here. Extraordinary how the chilled nettle soup matched exactly the colour of my rough piece of New Zealand nephrite jade!
I stood to speak of aquamarine at 7pm and finished my piece on emerald at 11.15pm: this after three 2-hour demonstrations made for a truly long, tiring but thoroughly enjoyable day.

Hatton Garden Jewellery Week Day 2

2008-06-12T09:43:00.008+01:00

The second day of Hatton Garden Jewellery week sees me arriving late into the Garden thanks to the tardiness of London Underground.

Another glorious day of bright sunshine. On my way to the Academy to prepare for my busy day tomorrow, I take time to study the “ultimate wedding dress” displayed in the window of the Wedding Ring Shop.

40 metres of hand woven silk with platinum thread have been used to create the £240,000 dress. It weighs 11 kg!

In the evening to Vivat Bacchus, the restaurant in Farringdon Street, for a Diamonds and Champagne evening. A group of non-trade people (and me) sampled various less well known champagnes while young ladies attended the event tried on the latest diamond jewels from Davril, of Hatton Garden.

Many camera phones employed to capture the excitement of diamond necklaces and rings appearing on female necks and fingers.
I networked with City currency traders, physiotherapists, Lincolns Inns lawyers, wine importers and advertising workers to hear their opinions on diamond quality, values, Hatton Garden and jewellery.
A De Beers Group employee spoke on diamond formation, diamond characteristics, conflict diamonds and famous diamonds. The evening finished with an auction of bottles of wine in aid of a Bart’s Hospital charity.

Hatton Garden Jewellery Week Day 1

2008-06-09T15:34:00.009+01:00

Day 1 Mon 9th June

The week starts well: a definite buzz around the Garden this morning – bright sunshine and street banners advertising the Jewellery Week greet all on the pavements. Off to flying start to the day with an interview with Jane Witherspoon of BBC London TV News. She’s in Langdales to learn from me about diamonds, Hatton Garden and the Jewellery Week.
Then to listen to classical singing on the pavement in the Garden – that must be a first. Lovely to hear pleasant, pleasing live music sung by soprano Sarah Mimms in the sunshine.
Next, to my ‘club’ in Bleeding Hart Yard for their open house and view the jewellery photograph exhibition.
Spot of lunch then to prepare for my first event – “Gem Talk & Wine Tasting with an Oriental twist” tonight.
6pm and I pitch up at 54 Restaurant, specialising in modern European and Malaysian food, on Farringdon Road at number, er, well, 54. Owned by John Vaughan, a rarity in being both a gemmologist and restaurateur. We are soon joined by 20+ diners intrigued to learn from me about gems and wine. Each of the dining tables was labelled with a wine producing country and wine from that country placed upon them.
In a relaxed and informal setting, Jenny from Holts Academy spoke briefly of the educational role of the Academy and I followed with a talk about myself and how when I sampled various clarets on a wine tasting course I used the colours of rubies to note subtle wine colour saturation differences. This lead me to think about attributes shared between gems and wine (more on these in a later post). I spoke further on the different gem varieties and those that originate in each of the chosen wine producing countries.
We tasted (no drank!) these wines and learnt more from each other on gems, wines and food. For the first time I drank and enjoyed red Brazilian wine!
On one of the warmest evenings of the year, the first day of Hatton Garden Jewellery Week ended splendidly with a meal offering “an Oriental twist”.

BBC and synthetic diamonds

2008-06-01T20:01:00.003+01:00

In May 2008 I was interviewed by BBC radio for an item on synthetic diamonds to be broadcast on their consumer programme 'You and Yours'. You can listen to the item at my website http://www.ericemms.com/news.htm.
After the interview the reportor carried out a vox pop in Hatton Garden to gauge the public's perception of man-made diamonds.

Synthetic moissanite – no longer a diamond simulant?

2008-05-27T14:41:00.008+01:00

Tues 13th May – To the Gem-A building (common parts surely in need of a lick of paint and new carpeting) to pay my £5 and listen to the latest Specialist Evening at their ‘gem discovery club’. Again, no tea or biscuits was on offer, before or after the talk – can’t be that expensive to put on such refreshments.
Synthetic Moissanite was the subject given by Mr Dennis Allen, an industry consultant and for the last two years business development consultant to Charles & Colvard, creator of the material. Mr Allen’s role is to increase the market for moissanite in the UK by finding new customers to sell the product.
When synthetic moissanite was introduced ten years ago it was promoted as a competitor to diamond. Now the emphasis is to market the man-made or “created” material as an “incredible near-colourless jewel” purchased by women for themselves. Marketing emphasis is placed on moissanite’s physical and optical properties. Charles & Colvard, the sole source of the material, claim moissanite “is not a substitute or simulant, but rather a unique jewel with exceptional brilliance and fire that delivers quality, beauty and value like no other”.
Sales in the UK are increasing through six independent retailers, TV shopping channels (moissanite is Ideal World Shopping channel’s top selling jewellery line) and catalogue retailers. Moissanite is sold in the UK mounted only in 18ct gold as a unique jewel, perfect for self-purchase indulgence or reward for an achievement: an affordable luxury.
Mr Allen covered the historical discovery by Henri Moissan in 1893 of tiny silicon carbide crystals (moissanite is SiC) recovered from a meteorite crater; the higher dispersion and higher refractive index (incorrectly marketed as being synonymous with brilliance) than diamond and moissanite’s relatively high degree of hardness (between 9 and 10 on the Mohs scale).
Moissanite is grown by Cree, Inc, a manufacturer of semi-conductors, using a “patent thermal growing process”. Roy Abrahams, an attendee of the talk, later found on-line patents describing the process as one of sublimation of source material onto a seed SiC crystal. The crystals grown are sold to Charles & Colvard who have them fashioned in the Far East to a unique set of proportions, slightly different to diamond, to achieve maximum brilliance. Moissanite, having a relative density (SG) 10% less than diamond, is sold in the faceted form, not per carat but per “diamond equivalent size”. Up to 15mm sized stones in a variety of shapes are offered with a “Certificate of Authenticity and Limited Warranty”.
Only “near-colourless, eye-clean” quality material is faceted hence no grading system is needed for moissanite. It has been claimed five intensities (grades) of green have been produced.
Mr Allen emphasised the primary customer for moissanite are middle-aged (35+ years old) fashion and value conscious women, and finished his talk with a brief recap of US and UK sales figures.

Supporting the confidence of diamond and gold purchasers

2008-05-14T18:48:00.008+01:00

May 8th 2008:

To the GIA campus in central London for the latest talk hosted by the London alumni group. Michael Rae, Chief Executive of the Council for Responsible Jewellery Practices (CRJP) presenting a talk “on reinforcing consumer confidence in diamond and gold jewellery”.
Michael brought his audience up to date with the work of CRJP, the international industry organisation whose members are dedicated to promoting accountable business practises. The council currently comprises of over 80 companies involved in the gold and diamond supply chain. More details at http://www.responsiblejewellery.com/

Michael stressed how a Code of Practices formulated by the Council after consultation with the diamond and gold industries will be implemented by member companies and monitored by independent auditors.

A fuller report of the meeting will be posted on the Alumni Group’s Facebook page

Disclosure: I have recently joined the group of ‘officers’ who organise these talks.

Russian Emerald and Facet Design Software.

2008-05-07T17:20:00.002+01:00

Tues 6th May.
To Gem-A off Hatton Garden for another Specialist Evenings. Anton Vasiliev of the production company LAL of Moscow gave a three part talk. The first part was on Russian emerald deposits.
Emeralds were discovered in the Ural Mountains in 1839 at the Marinsky mine near Malysheva where temperatures drop to -40 degrees Celsius in winter. After the Second World War the mine was exploited to extract beryllium, a strategic element needed in the nuclear industry, from the beryl crystals. Extraction of ore has not been carried out since 1993: all emerald have been recovered since that date by reworking ore from old tailings. Emerald and green beryl crystals are separated by scrubbing, sieving and hand sorting (sorting carried out by the careful eyes of women working in freezing conditions)
The crystals are graded for colour using a No1 to No 5 scale, the most saturated green being graded as No.1 (pale No. 5 crystals are deemed to be green beryls and not emeralds. Separate grading scales are used for bluish green and yellowish green crystals.
Alexandrite (another beryllium gem) is found at the mine but 100 to 200 times as rare as emerald. Upon questioning Anton said the emeralds contain tremolite fibres but lack pyrites inclusions. The emerald are cut and polished in Russia.
Anton then spoke of his spectroscopic research on emeralds. From the o- and e- ray directions spectra of Afghan, Ural, Colombian, and Zambian emerald were shown. A flux-grown synthetic emerald has a sharp chromium line in the red, Anton called the ‘R-line’. Afghan emeralds have a similar spectrum indicated their pure green colour is solely due to chromium. Russian emeralds have a broad absorption in the deep red due to iron so these emerald do not show red under the Chelsea colour filter. In the Colombian emerald he ran, chromium and iron were absent: its green colour entirely due to vanadium. A Zambian emerald should the chromium peak and the iron band (Anton called the broad Fe band the ‘aquamarine’ band). He has written a software suite which calculates the CIE colour co-ordinates from the visible absorption spectrum, making allowance for the thickness of the stone. However, Anton did not show interest in the concept of colour communication using values for hue, saturation and tone and indeed had not heard of the gem e-wizard software.
The final part of the evening was taken up by Anton demonstrating the software he has written to generate facet diagrams for gem cutters. His software produces a transparent solid depiction of the facets of any design he can quickly create (similar in look to images generated by the Sarin measuring instrumentation) which takes into account the position of illumination and the colour ambiance of the surrounding environment. I was pleased Anton said that beauty in a gem cannot be described or created by his software: his software, he said, should be considered a tool to aid the artist facetor. He works with Pascal programming and uses polygon algorithms not ray-tracing methods.
A fascinating talk from someone struggling at times with his English (not complaint from me though). Such a pity so few attended.

From Yakutia with Love

2008-04-25T15:13:00.003+01:00

Illustrated talk on Tues 8th April 2008 at Gem-A London by Alexandra Russell-Stoneham

Miss Russell-Stoneham shared some of her research on the Russian diamond trade she carried out during her time in St Petersburg. She works in the diamond industry in London.

The Russian diamond industry is a mystery. It is an intricate history of secrets, scandals and politics. Seeking a clarification of the present situation Miss Russell-Stoneham sketched an outline of the key players: the Russian and Yakutian government (Yakutia is a federal republic of Russia), ALROSA and Gohkran.
Russia produces 25% of world’s diamonds by volume and has the biggest kimberlite pipe mine at Mirny.

ALROSA was created in 1992. It is a Russian company involved in diamond exploration, mining and sales of rough diamonds, and diamond manufacture. ALROSA accounts for 97% of all Russia’s diamond production. Its share in the global rough diamond production is 25%. It is a closed joint stock company owned by the governments of Russia and Yakutia, employing 35,000 personnel.

Gohkran is the Russian State Treasury set up in 1920 to look after state resources and other valuables. Someone has estimated Russia has $12 billion of rough diamonds, most stored in secret vaults under Moscow streets.

Russian diamond statistics were a state secret. During industrialisation of the nation during the 1920s and 1930s there was an increasing need for industrial diamonds. All were bought abroad as no Russian diamond sources were known at that time. As the “Cold War” started, the US forced an embargo on exports of diamonds to Russia. The Soviet response was to prioritise secret expeditions to discover diamonds sources from the Urals to the Pacific coast. Similarities between the geology of diamond bearing areas of South Africa and areas in Siberia (now Yakutia) lead to discoveries of large sources of diamond. The secret code used to transmit to Moscow the news that diamonds had been discovered in Siberia by Soviet geologists was “I’m smoking the Pipe of Peace”: the “pipe” mine found in 1955 was called “Mir”, Russian for ‘peace’. Following this period, Soviet government motivation was to develop more mines and investigate the production of man-made diamonds.
In the Mirny region, 10,000 workers, fired (it is claimed) by patriotism, housed in a newly built town, toiled in poor conditions of a seven month winter with 30 metres of ice and a flooded mine in summer.

De Beers, determined at that time to monopolise the global supply of rough diamonds signed a deal to purchase all of Mirny production. This deal between two opposing ideologies was cloaked behind a number of intermediate trading companies, one known as the “City and East – West Limited”. To the Russians the arrangement offered the attractive benefits of stable guaranteed prices from one buyer and an exchange of technological expertise.
In the late 1950s Russia established their own diamond polishing industry: fine quality, well proportioned stones in small sizes and precise standardisation began to appear on the diamond markets in the decades that followed. These Russian goods, nicknamed ‘Silver Bears’ by some in the trade, were rumoured to be synthetic. De Beers is said to have asked a sightholder and a broker to investigate this rumour.

The relationship between the Russian state and De Beers endured despite suspicions on both sides. Their ‘affair’ was finally ended by an investigation and ruling on the relationship by the European Commission in 2003. De Beers, now known as the DTC, no longer buys rough from Russia.

Today ALROSA is seeking new marketing channels, exploring more in Yakutia and is investigating investing in African sources.

Jade talk

2008-04-02T18:28:00.012+01:00

Continuing the SE Branch evening described below, Mr Alan Jobbins, the octogenarian President of the Gemmological Association presented an illustrated talk on Jade.

Visuals used were aged 35mm transparencies, many taken over 25 years ago, projected from a carousel slide projector. Unquestionably “low-tech” equipment but, in contrast to the last Gem-A talk I attended (see below), the visuals worked perfectly and the green colour rendition was satisfactory.

Jobbins took the audience on a brief tour of jade. From the colours seen in polished jadeite and nephrite; the brown weathered surfaces of “river jade” and “mountain jade” boulders presenting a colour contrast to the boulder interior for the skilled jade carvers to exploit; how colours of jade can be altered by heat and staining; the chemistry of the jadeite-diopside-acmite clinopyroxene series and the tremolite-actinolite series of nephrite; the fibrous nature of jadeite and the more granular nature of nephrite (illustrated by polished thin sections so beloved of mineralogists), the colour names and quality of imperial, commercial and utility jade offered for sale at auction in Burma, to the geographical localities of jade found at the boundaries of tectonic plates, the movements of which create the high pressures and high temperatures require to form the two forms of jade.

Nothing new in the talk: but a useful summary for the few tyro gemmologists and students present.

South East by Southampton Row.

2008-03-31T17:14:00.005+01:00

To Southampton Row in Holborn, familiar to me from my student days when I studied at King’s College London, to attend the AGM of the South East branch of Gem-A. The UK, as you may know (or may not care), is divided into a dozen regions, not entirely for administrative purposes. Gem-A has six UK branches, catering (I assume) for provincial members.

I have always thought it strange for the need for a South-East branch, as most of their meetings seem to be held in Central London, reasonably close to Gem-A HQ in Greville St/Saffron Hill. No matter - the official boundaries of the South East are themselves perverse: enclosing a mixed bag of eight counties to the west and south of the capital, from the north of Oxfordshire to the east coast of Kent and from the south coast of the Isle of Wight to the west of Hampshire. I am not sure any gemmologists living close to these county boundaries would travel to Central London to attend “their” regional Gem-A branch meetings.

Following coffee and biscuits (better fare than at Greville Street – but not as enjoyable as the wine and nibbles at GIA-London) and the AGM, an illustrated talk on jade by Alan Jobbins was offered (described above).

Brand Values at Selfridges

2008-03-27T16:49:00.001Z

I find myself at Selfridges, my ‘local’ departmental store in the West End of London. Not to see again the jewellery brands of Bulgari, Cartier, Chanel, H. Stern, Kojis, Theo Fennell and Tiffany arranged in the Wonder Room but to the basement.

Here tucked away on display are copies of advertisements for the Selfridge store published close to the date the store was built and opened in March 1909 by Gordon Selfridge, the American retail magnate. He was one of the first retailers who attempted to make shopping a fun experience instead of an unpleasant necessity. Goods were put on prominent display so shoppers could handle and examine before purchase, staff were taught to assist shoppers and not to sell aggressively and he put into place other practises that made it easy and agreeable for customers to shop in his store: many of which have been adopted by modern stores throughout the world.

One of the old advertisements caught my eye and caused me to stop, linger and consider its text. It was a declaration of Gordon Selfridge’s retailing ethos; a list of four principles Selfridges considered to be, almost 100 years ago, of paramount importance to the success of the newly constructed store. These four principles were the precursors of today’s value statements, now created to define a particular brand. Selfridges called these four elements “Foundation Stones”. Just as his new store was built strongly on Oxford Street foundations, his retailing philosophy in London was to be built on these “stones”.

The “foundation stones” listed in the advertisement are;

Integrity
Sincerity
Courtesy
Value

Looking at this list made me consider that we, in our business of “precious stones” and jewels could do worse than to adopt these 100 year old “foundation stones” as a basis of our personal reputations.

Buying Zambian Rough

2008-03-24T18:11:00.007Z

18th March
To the Gemmological Association, paying my five pounds fee for another Tuesday evening Gem Discovery talk, this month given by Mr Guy Clutterbuck, a coloured stone mine investor and gem dealer. Guy has been buying African rough gems from source for the last twenty-five years.

The thrust of his talk was his investment in East Zambia, close to the border with Malawi. His business model is to invest in Africa by giving small sums of capital to the local African diggers and in return winning the first pick of the rough emeralds and aquamarine found. He believes if one goes to Africa to buy without winning the trust of the locals, one is never offered the best gem material so Guy spends months living with the villagers building up a good rapport and forming bonds of trust and friendship with the locals.

The mining area is 800 miles from Lusaka, 20 hours in a Land Rover over poorly kept roads. The greatest danger for Guy apart from a road accident is malaria. The mine was discovered in the late 1960s and is now a deep pit of solid quartz, extremely hard to dig with picks so explosives are employed on occasion. The emeralds are of fine colour and Guy prides himself on the “double blue” colour of the aquamarines – not enhanced by heat.

Twice a year Guy goes to the mine, pays the miners more in dollars per gram than other buyers and takes the rough crystals to the Far East where they are cobbed with pliers along fracture lines, sawed into performs and cut and polished. The emeralds are fashioned so there is a pleasing balance of yellowish green with bluish green. His emeralds are clarity enhanced with resin. Guy sells the fashioned gems in Europe and the US.

A fascinating talk marred by the poor state of the audiovisuals. The DVD presentation of the mining area was delayed for ten minutes while the inaudible soundtrack was corrected and the projection of Guy’s slides lacked saturation in the colour rendition of the emeralds fashioned from his rough. I must add these equipment defects were not the fault of Guy.

Passion For (cultured) Pearls

2008-03-17T18:36:00.007Z

Wed 12th March

To Bloomsbury (is this also a village, perhaps?) for the latest GIA London alumni talk in their airy and modern campus.
Chrissy Douglas of Coleman Douglas Pearls presented a talk, more of an enthusiastic chat, on 'The Practicalities of Selling Pearls to Retailers'. The sheer passion for her stock-in-trade, her love of handling each cultured pearl she sells and her great joy in learning something new each working day struck me as I listened. She is a self-taught designer and cultured pearl specialist, born in Mexico to artist parents, lived at an early age in an environment of colour and texture: designing was always in her blood. With a retail store in Beauchamp Place, London, she has an international brand loved by celebrities and sold around the globe.
Her chat encompassed the value of cultured pearls, what is a pearl, pearls in history, types and geographical localities, how to buy and care for cultured pearls: for beauty and for wealth.
I particularly enjoyed Chrissy retelling the story of the famous pearl 'La Perigrina' being chewed by Elizabeth Taylor's pet dog. The pearl is one of the most famous natural pearls, approx 17.5 x 25 mm and weighing 202.28 grains (50.6 carats), it was discovered in the Gulf of Panama and given by Phillip II of Spain to his wife, Mary Tudor of England. The pearl passed down through Spanish royalty, through to the son of the Emperor Napoleon III of France to the British aristocrat the Marquis of Abercorn. In 1969 it was purchased $37,000 Richard Burton as a Valentine's Day gift for Elizabeth Taylor. Today the famous pearl retains the bite marks of the pet pekinese.

From Hatton Garden to Kashmir

2008-03-07T18:34:00.002Z

4th March

Arrived late at Gem-A HQ off Hatton Garden this evening, paid my £5 fee and sat down to hear Mr Haji Abdul Majid Butt talk of the new Kashmir sapphire mines.

The geologist and gemmologist is the former general manager of the Jammu & Kashmir Minerals company, an Indian government exploration and mining concern http://www.jkminerals.com/.

He told of the hazards of journeying to and mining the gem deposits in spectacular mountainous terrain at 4,500 metres. The locality, in the Paddar area of Kashmir between "longitude 76 Deg.-15 Deg. and 76 Deg. -30 Deg.", was illustrated with maps and potential future production caratage was given.

The government plans to auction parcels of the sapphire rough in the near future.

From Hatton Garden to the Argyle Mine

2008-03-02T19:25:00.003Z

Sat 1st March.
Pop round to my newsagent to buy my usual edition of the FT (the Financial Times sometimes has informative articles on the gem and jewellery industry), turn to Page 3 (no, of course the FT is not that kind of naked paper) to be confronted with an article "Soaring Gold Causes Jewellery Pandemonium" on the high prices of gold and platinum affecting the pricing of jewellery in the shop windows in the "Garden":
Jewellers in London’s Hatton Garden – the capital’s jewellery quarter – are raising the price of wedding bands on a weekly basis, with less-expensive palladium rings now coming into vogue. “The price of platinum has been going up so fast, we’re quoting people prices for platinum wedding bands on a Saturday and saying we can’t guarantee the same price on Monday. Last week, we had to raise the price of all our platinum items by 30 per cent,” said a manager at Hatton Garden jeweller.The rise in prices has made less-expensive palladium wedding rings – which are lighter, but nearly identical in colour to platinum or white gold ones – more popular, London jewellers report. “In a period of five months, the price of platinum has doubled and the making of a platinum ring which once cost £300 now costs £600 ($1,200), but palladium, only costs about £10 per gramme. It’s quite light and doesn’t tarnish and you wouldn’t notice much of a difference between a palladium ring and a platinum one,” said a manager at another jewellers.The price of gold hit a record $975.90 on Friday, ending European trading at $970.40 a troy ounce, while platinum hit a record $2,158 a troy ounce last week.
Then turning to the FT glossy magazine I see on its cover a terrific colour picture of the Argyle diamond mine in the Kimberley area of North West Australia, giving a clear idea of the sheer size of the mine. If you a diamond student (DGA or GG) please try to obtain a copy. The accompanying article "Mine Is The Glory" is a travelogue of Western Australia; the author travels to the Argyle mine and to Broome, home of the Australian cultured pearl industry. The article contains a few "nuggets" of information.
"The Argyle diamond mine...is a pair of dung-brown hills sited on ancient Aboriginal lands. In less than 30 years since being discovered it has become the source of nearly a third of the world's diamonds, as well as the sole supplier of the almost freakishly beautiful intense pink stones that can be worth up to 20 times as much as white diamonds."
None of the 800 miners "ever sees a diamond...What gets sent for processing in Perth 1500 miles away...are crates of tiny, broken-up rocks in telltale grey-greenish colour a bit like cat litter. This mineral is lamproite and, on average, one pebble in 400 is a diamond. Of that one in 400, one in 50 is a pink diamond. A smaller proportion still - far fewer than one in a million of those pebbles - conceal the ultimate intense pink stones...stones of exceptional rarity and dizzying value."

Coutts London Jewellery Week

2008-02-24T18:09:00.002Z

For the first time the London gem and jewellery industry will be showcased in a five day festival sponsored by Coutts bank. Details of the week 11th to 15th June 2008 can be found here.
I will be offering two seminars in Hatton Garden on the final day. They are titled "How To Buy Diamonds and Coloured Stones" and "Famous Precious Stones".

Designs In Bermondsey

2008-02-23T19:10:00.004Z

18th February
To Bermondsey to witness the presentation of jewellery designed and fabricated by a few of my recent gem students. Bermondsey is an interesting area south of the Thames; centuries ago a place thick with leather tanneries and warehouses and now quite a fashionable "village". Have you noticed that all areas of London are now described as "villages"? - I am said to live in Marylebone village but I am not sure whether I work yet in Holborn village.
The jewellery design students attended a short course at Newham College in East London (presumably in Newham Village) and their work was exhibited at the Fashion & Design museum in Bermondsey Street, a creation of Zandra Rhodes.
The students showed impressive talent and a number utilised coloured stones in their designs. Yet that phrase "semi-precious stones" still seems to retain some currency in the minds of students; how I wish I could banish it! Does not everyone appreciate all gems are "precious"?

Valuing one of the largest diamonds

2008-01-27T17:34:00.000Z

Gem lectures in London are like London buses. One sometimes endures a long wait for one to come along and when one finally arrives another follows along very quickly. After the previous day's talk on natural pearls, on Wednesday 23rd January, I attended a talk at the Gemological Institute of America (GIA) campus in London given by Mr Peter Buckie on valuing one of the largest diamonds.

Peter has been valuing gems and jewellery for many decades. He is an international jewellery valuer and runs the Jewellery Evaluation & Mediation Service. His talk was titled “The challenge of valuing one of the world’s largest diamonds – a valuer’s dream or nightmare?”

Confidentiality: Peter started his talk by stated that most of his work on valuing the diamond must remain confidential and cannot be shared with the audience. He had been retained by the foreign vendor of the diamond to provide the open market value of the diamond, that is, its value if sold at public auction. Two other valuers were also commissioned to value, one from Paris, and the other from Geneva. The three independent valuations would be compared and were found to be within acceptable tolerances of each other.

The faceted diamond is over 200 carats, D-colour, Internally Flawless, Excellent Symmetry, Excellent Polish and it exhibited no fluorescence. Accompanying the gem was a letter from the GIA stating the diamond is the largest one of its shape and quality graded by the GIA at the time of grading in July 2006. The gem also had a Kimberley Process Certificate stating its weight in its rough state (over 600 carats), its country of origin and its value in the rough state.

Peter’s spent three weeks on the assignment and his valuation was 14 pages long, detailing all the research he undertook and explaining his thought processes in arriving at his valuation which was several millions of US dollars.

Research: GIA had confirmed the diamond is still the largest D/IF example of its shape they have graded. Auction records were consulted and the prices achieved by very large diamonds sold recently at auction were investigated. The world record for a colourless diamond was achieved in 1995 when the Star of the Seasons diamond, a 100.10 carat pear brilliant D/IF stone sold for $16,548,750 and the 84.37ct D/Flawless round brilliant cut diamond, now known as the Chloe diamond sold in 2007 for $16,200,000. However private sales are not a matter of public record. This diamond was to be sold by private treaty. Clearly there were no comparable stone values in the public domain.

The data on larger famous diamonds were consulted and a table of the world’s largest diamonds, their weights and values was compiled but few have been precisely graded and their values known. Opinions were sought from the international auction houses, international diamond dealers in London, New York and the Middle East. In addition, international business contacts were canvassed. Venture capitalists, investment bankers and alternative asset brokers were approached to learn the likelihood of someone investing the likely substantial value in a single diamond. The market for such a diamond was clearly limited. Peter concluded his research by establishing a level of value, an open market value based on comparable diamond data in the public domain.

Possible Value: A very speculative and subjective range of value was proffered in his valuation. In essence the diamond’s value is “what anyone is prepared to pay for the kudos of owning the world’s largest D/IF diamond ever graded by GIA”. Peter confessed the precise value was impossible to estimate.

Justification for Peter’s value: His value range was based on past prices paid on all known comparable diamonds, the prevailing economic conditions and diamond market conditions at the time of the sale, and the current and perhaps future saleability of the diamond.

Peter concluded his talk by informing his audience he has commissioned a model of the diamond to be made in cubic zirconia.

Pearls - A Natural History

2008-01-27T15:59:00.000Z

On Tuesday 22nd January 2008, Mr Mohammed Jabir gave an illustrated talk on natural pearls at the Gem-A in London. Mr Jabir, a natural pearl dealer based in Kuala Lumpur, travels extensively buying and selling pearls. His family has been in the pearl business for generations.

He started his talk by drawing attention to the distinction between natural pearls and cultured pearls then considered the ancient history of the subject. Hindus believe their god Krishna discovered the first pearl. Pearls have been found in ancient Egyptian tombs. The Chinese had their dead buried with pearls under their tongues and the Romans invaded Britain for the river pearls. The Maharajas of India wore pearls extensively yet primitive cultured pearls were produced in the third century.

Turning to Moments of History, Mr Jabir related that the prophet Mohammed carries a pearl from the Red Sea to Damascus in the seventh century. Columbus sailed to the New World to find pearls for the Spanish treasury and Native American Indians jealously guarded their valuable river pearls from the newly arrived Europeans. Catherine the Great, Napoleon and Queen Victoria are historical figures who loved pearls.

Modern History: The pearl fisheries were the Persian Gulf, the Gulf of Mexico, Baja California and the Mannar straits. River pearls from the US were popular in the 1800s to the mid-1900s. Natural pearls were popular in Europe and the US in the late 18th century to the 20th century. By the turn of the 20th century there were three pearl dealers for each diamond dealer in the global markets. Today there must be thousands of diamond dealers for each natural pearl dealer.

The Decline of the Natural Pearl Trade: the 1930s economic depression coincided with the introduction of the Japanese beaded cultured pearl to the global gem market. The discovery of oil in the Persian Gulf led to pearl workers seeking alternative jobs in the oil industry and finally the pollution of the Gulf accelerated the decline in the pearl trade.
Modern History: Cartier obtained their New York headquarters in Fifth Ave by exchanging with a lady client a pearl necklace for the building. Before the Wall Street crash in 1929 the major buyers of pearls were the Maharajas of India, European aristocracy and the leading families of the US nouveau riche.

Natural Salt-water Pearls: Before the 16th century the fisheries were in the Persian Gulf, the Red Sea, the Mannar straits and also the Philippines. After the 16th century Mexico, Baja California and South Pacific became important pearl fisheries. Today, there are practically no fisheries. Perhaps the only known fishery today is off the coast of Kuwait but the production of natural pearls is insignificant.

Cultured Pearls: Came to dominance after WWII. By 1960s few natural pearl dealers were left in the former pearl trading centres of Bahrain, Dubai, Basra, Bombay, Paris, London and New York. The price of cultured pearls (with a bead nucleus) reached a new high in the 1970s and 1980s until the introduction of the Chinese freshwater cultured pearls (without a bead) priced at a fraction of the Japanese beaded cultured pearls. Today Japanese cultured pearls can be bought at prices far less than 20 years ago.
Revival of Natural Pearls: Mr Jabir claimed educated consumers are aware of the price decline of Japanese cultured pearls. They realise the true value of natural pearls, that there is no new production of natural pearls and that the marker is restricted to reselling of old natural pearls. Prices of natural pearls continue to rise.

Today’s Market: A natural pearl necklace formally belonging to the Duchess of Windsor sold by Sotheby’s in 1987 was sold again at auction in 2007 for $3.2 million. A two row pearl necklace of Maharaja of Baroda pearls sold recently for $7.1 million. Famous pearls such as the Regente, the Pelegrina, the Mancini and the Tavernier pearl have been sold at auction in the last 15 years. The new wealthy collectors of natural pearls are from the Middle East, Russia, China and Russia. Very high prices for natural pearls have been realised in Hong Kong, a city without a natural pearl market 15 years ago. The jewellery houses of Cartier, Tiffany and VCA selling natural pearls in the 1930s are now active in retailing natural pearls. Also retailers such as Graff and Moussaieff sell natural pearls. The biggest collections of natural pearls belong to Sheikh Khalifa bin Zayed Nahyan of Abu Dhabi, the Sheikh Nasser Al-Sabah of Kuwait, the Sheikh Hamid Bin Khalifa Al-Thani of Qatar and HM Queen Elizabeth. Mr Jabir told us the Queen only wears natural pearls and her favourite piece is a two row necklace given to her by the Maharaja of Patiala.

Current situation: More international gem dealers are learning about the natural pearl market. Christie’s are holding a strong natural pearl auction in Spring 08. Bahrain, Kuwait, UAE and Qatar are establishing pearl museums and pearl research centres.
The international gemmological laboratories are gaining a broader knowledge of natural pearls. There will be a continuous growth in demand for natural pearls yet a lack of talent and know-how exists in the industry. Dubai is attempting to revive its pearl industry and new natural pearl markets are being created in Bombay and Hong Kong.

Mr Jabir concluded his talk with reference to the “Book of the Pearl” by Kunz as the finest book written on the subject and to the current exhibition on natural pearls being held in the National Natural History Museum in Paris until the 10th March 2008.
I asked Mr Jabir about natural pearl treatments, in particular, that of surface polishing. He replied that if the polishing of the surface of natural pearls is disclosed on a gemmological report, the pearl value would be reduced.

How modern gem treatments affect the gem and jewellery industry

2008-01-09T10:19:00.000Z

The impact of modern gem treatments on gemmology and the gem and jewellery industry

Thirty years ago, the time I joined the gemmological profession, the greatest concern of the gem and jewellery industry was the proliferation of artificial gems and diamond imitations such as cubic zirconia, Gilson synthetic emeralds and Raumara synthetic rubies. However when such products had been investigated by gemmologists and identifying obtained the products were readily detected.

Currently the most expressed concern is the prevalence of gem treatments. Enhancements designed to alter the appearance of diamonds, coloured stones and pearls are being introduced to our industry at an increasing rate. The latest treatments challenging gemmologists are those that cannot be detected readily but require the implementation of advanced testing instrumentation, expensive to acquire and maintain, and a higher degree of specialised knowledge to obtain and interpret data gleaned from such equipment.

Current treatments, such as High Pressure, High Temperature annealing of natural and synthetic diamonds, the secondary enhancements following such HPHT processing, and the so-called Beryllium-diffusion of sapphires and rubies, cannot be detected by gemmologists using standard gemmological equipment or with instruments seen in well equipped gemmological laboratories a decade ago.

A further challenge to gemmologists attempting to keep their knowledge current with the latest developments in synthetic gems and gem treatments is to share this knowledge with the gem consumer in order that the consumer considering purchasing jewellery is fully aware of which forms of treatment a gem can undergo, knows how such treatments can be detected and how best the enhanced gem should be described.

The impact of the increasing numbers of modern gem treatments is thus two-fold:

Gemmologists must obtain and deploy sufficient resources in order to detect all gem treatments. Only well capitalised gemmological authorities will have the monies to invest in advanced research-grade instrumentation. Only they will be able to attract and retain personnel with the expertise to manipulate the instruments, obtain and interpret the data obtained (usually spectroscopic information) and test hypotheses regarding the sub-atomic mechanisms that alter the appearance of treated gems. Such personnel will be not gemmologists but post graduate solid-state physicists.

In order to maintain consumer confidence in the gem and jewellery industry, gemmologists must communicate to consumers all the possible treatments a gem can undergo, the necessary means of identification and the proper ways of describing such gem treatments.

2008-01-03T16:24:00.000Z

Diamond Grading- A Practical Guide.

Eric Emms offers regular practical diamond grading courses in association with various teaching establishments. In 2008 monthly week-end courses and one 5-day course in May are being offered in association with Holts Academy ofJewellery.
The courses are popular and are limited to ten attendees.

Key Benefits
Learn to grade diamonds like a professional.
Understand the terms used by the industry to describe diamond quality.
Understand and identify diamond treatments (laser drilled and fracture-filling).
Identify simulants (CZ and moissanite) and gem-quality synthetic (man-made) diamonds.
A short 'taster' for those considering a career in the gem and jewellery industry.
A revision for those au fait with grading
Advice on further gem education
Consultation on diamond-related subjects.
Know more: Sell more!

What attendees said about the June 2007 course
"Great for pointing me in the right direction to continue my studying and very generously gave me some valuable contacts I was struggling to get"
" Cheerful, informal, knowledgeable, pleasant surroundings...really felt I was beginning to know how to look properly at diamonds"
" It has exceeded my expectations in terms of enjoyment"
"It has been very calm and relaxing, yet (an) informative way of learning....I feel far more knowledgeable in the subject now with a view to learn more"
"It has improved my confidence, knowledge and excited my curiosity"
" Everything was explained in both 'novice' and trade 'lingo' and Eric was more than happy to explain one-to-one and repeat anything that was not understood the first time around"

What the attendees said about the tutor, Eric Emms
"Very good. Very interesting and enthusiastic"
"Excellent"
"Very interesting and insightful"
"Very helpful, described things well"
"Eric Emms was very good in explaining everything"
"Very helpful and interesting"

HPHT views from DTC

2007-12-19T21:16:00.000Z

6th Dec

Off to the GIA London campus in Bloomsbury for the latest lecture arranged by the local alumni group. Approx. five to six lectures of gem and jewellery related topics are offered to an evening audience of gemmology students, recent gem graduates and professional gemmologists such as myself.

The latest talk was presented by Dr David Fisher, Principal Scientist at the DTC research centre (in centre of picture).

Dr Fisher outlined the basic threads of their work related to maintaining consumer confidence in gem diamonds, the major one involving their research on High Pressure High Temperature treatment of diamonds. Topics covered included the change in diamond colour occuring owing to diamond type (ie IIa, IIb and Ia), analysis of the photoluminscence spectra of natural and HPHT-treated diamonds and the investigation of secondary irradiation treatments following HPHT processing. Artificial coatings applied to surfaces of polsihed diamonds were briefly mentioned.

The next talk will be on 23rd January. Details at http://www.gialondon.co.uk/

December Practical Diamond Grading Course

2007-12-09T09:36:00.000Z

Last week-end saw my last course of 2007. In the past offering a diamond grading course in December would attract little response from the UK gem and jewellery trade as one assumes potential attendees would be more occupied placing and selling diamonds at work than learning off-site with me in the busy run-up period to Christmas. However last December I decided to see if there would be any interest in a December course and was delighted that course was fully subscribed and last week-end there was a very good attendance. A greater fraction of the attendees are now "non-trade"; people who wish to change careers (many are swapping out of financial services in the City) and those in other careers who want to know more on the subject of diamonds and diamond grading.
The 2008 dates for my Practical Diamond Grading Course have now been finalised. New for 2008 is a Five-Day Diamond Course to be held in May. Full details from Holts Academy of Jewellery
http://www.holtsacademy.com/node/69
http://www.holtsacademy.com/

Trying To Define Diamond's Beauty

2007-11-11T17:16:00.000Z

Diamond's quality is defined by the so-called 4Cs but do they describe the brilliancy and sparkle of the gem? A few methods to measure, grade and report upon how well a diamond has been fashioned to maximse its optical properties have been published, notably by Russian and American optical scientists. The diamond trade is becoming familiar with the GIA cut grade system as printed on their modern round brilliant diamond grading reports.

On Tuesday 6th November I attended a presentation at Gem-A by Diane Flora, Director of Education at the American Gem Society on the AGS Cut Grading System used by their Diamond Grading Laboratory. I first met Diane in 1999 when as a GIA course instructor she gave one of the first GIA courses in London before the establishment of the GIA-London campus in Bloomsbury, London.

Tuesday's presentation briefly outlined the Angular Spectrum Evaluation Technology (ASET) as used by the AGS lab when grading the cut grades of round brilliant and square modified brilliant (Princess) cut diamonds. Essentially, computer software is utilised to measure the light performance of diamonds and is illustrated in three colours to denote light intensities exhibited by the gem. The light performance (LP) is graded by the software in a range 0 to 10 (zero being the finest). Note LP is not the cut grade as the latter is affected by any symmetry errors (eg shallow crown height).

The system is claimed to be distinct from the GIA cut grade system as the latter is based mostly upon a diamond's proportions whereas LP is the major component of the AGS method.

Pity the consumer now faced with more potentially bewildering data offered to him/her when shopping for a beautiful diamond. Further info on the AGS system as at http://www.agslab.com/research.html

Facebook Group

2007-10-16T05:58:00.000+01:00

Well it had to happen I suppose, the "group" has been created.
Explore it at
http://www.facebook.com/group.php?gid=5901648906
Anyone having participated at one of my grading courses can "join".
Let's see how many!

Pawnbroking

2007-10-14T15:43:00.000+01:00

Friday 12th October.

A brisk walk to the Royal Lancaster Hotel, on the north side of Hyde Park, for the annual conference of the National Pawnbroking Association.
I had been invited to give a brief presentation of "knowing a girl's best friend": I outlined what pawnbrokers should be aware of when examining diamond jewellery with a view to lending cash. I reviewed identification of diamond; its simulants and its treatments, and spoke of the benefits of diamond grading reports. Knowing ones limits of diamond knowledge and when to call in specialised diamond expertise (hopefully me!) is always essential. I finished by emphasing that all of us in the gem and jewellery should appreciate and celebrate the beauty of diamond.

Much was made at the conference of the benefits of pawnbroking to the public. Against a background of the slowing UK economy and an uncertainty in financial circles, the ability to quickly access an immediate short term cash loan at a pawnbrokers pledged against ones jewellery is becoming more attractive to increasing numbers of people. Pawnbroking is a fast growing sector of the UK jewellery industry: the two largest companies (in terms of numbers of shops) Albemarle & Bond and Harvey & Thompson, both quoted companies, have recently reported good results, see here and here.

Over coffee I met a jewellery valuer who reminded me that I had taught him diamond grading in 1980. He must have been on one of the first courses I taught. This started me thinking upon how many have attended my courses over the years at Sir John Cass, Gem Testing Lab, Gemmological Association and now at Holts Academy. Must be hundreds...perhaps I should start a networking group of my "graduates" on the web! Anyone for a Facebook group?

Loughborough 2007

2007-10-06T07:52:00.000+01:00

Saturday 22nd September

Off to Loughborough for the annual National Association of Goldsmiths Registered Valuers’ Conference.
A time for meeting more old friends and for more talking and networking over the week-end.
First, participation in a panel of four at “The Great Debate” namely ‘Diamond Grading Reports are not Worth the Paper They Are Written On’.

I opposed the motion by first describing briefly my career: I have spent my entire working life since 1978 in Hatton Garden examining and grading diamonds, and issuing diamond reports: I amusingly offered the view that I had wasted my career if the audience voted for the motion!
I outlined the functions of a diamond grading report; namely as a document of diamond identification, as an independent third party expert opinion on diamond quality and its use as a selling tool at a time when consumers are demanding to know more of the diamonds they are buying.
Stressed the reputation and expertise of the laboratories which issue the “paper” is a paramount consideration, I illustrated this point by referring to and comparing the reputation and standing of bank notes issued in Britain and Zimbabwe.
I concluded by asking the audience how many valuers present referred to diamond reports in their valuations or working notes. A unanimous response demonstrated powerfully the value of diamond grading reports. At the vote, the audience vigourously defeated the motion by a substantial majority.

The next day my talk on Tanzanite: Gemmology & Grading
In an overview of this increasing popular gem, in keeping with the light hearted tone of the week-end, I briefly presented the gemmology of tanzanite, its discovery in northern Tanzania, its trichroism, its colour and the reasons for colour. The brittle nature of tanzanite was also illustrated. How tanzanite can be identified was explained and the common simulants of tanzanite were listed. I declared that the first impact of a coloured gemstone was its colour and concluded my talk with a very brief look at colour science, how colour can be described and communicated, and how tanzanite can be graded for colour saturation and clarity.

Gemmological Talks

2007-09-30T07:11:00.000+01:00

September was an unusually busy months for talking!

At the annual gem and jewellery fair at Earl's Court (known for some reason as International Jewellery London) there were old friends, present clients and past diamond students to converse with and catch up with the latest industry news and, yes, gossip.

On Tuesday 4th, I presented one of the fair seminars in a small room above the exhibition hall. My subject was tanzanite: its occurrence, its gemmology, how it can be identified, its brittle nature and how it colour may be graded for quality.

Later in the month, off to Harrods for tea with scores of ladies! Actually this was a congregation of customers who buy gem jewellery on a leading TV shopping channel. I gave a brief talk of gems: their beauty, how they are altered to improve appearence and their correct description. Many ladies who talked to me after were interested in how best to care for their gems and where they could learn more about diamonds and my diamond grading course. What struck me was how knowledgeable some of these consumers are: one lady expressed that it was the "marked trichroism" of tanzanite that she found attractive in the gem! This was the first time I have heard a consumer use this gemmological term. Evidence that the public are interested in gems and want to learn more.

My Diamond Grading Courses At a New Venue

2007-09-09T08:14:00.000+01:00

LEARNING ABOUT DIAMONDS IN A NEW SETTING

On 23-24 June 2007 I presented my Practical Diamond Grading Course at a new London venue. For the first time Langdales Jewellery Centre in Hatton Garden played host to my week-end diamond course. The practical course, tutored by me and run under the administration of Holts Academy of Jewellery, demonstrates to students the range of quality occurring in diamond. Emphasis on clarity and colour grading is given and the topics of diamond proportions, weight, diamond treatments, simulants, gem-quality synthetic diamonds are considered with examples available for each student to examine.
Attendee Jade Watt commented after the course "Great for pointing me in the right direction to continue my studying and Eric very generously gave me some valuable contacts I was struggling to get".
I like the new venue; “The brand new building Langdales, now the home of Holts Academy, is an ideal Hatton Garden base to teach my courses; all my students enjoyed learning in the comfortable meeting room”.
Further diamond grading courses will be offered by me at Langdales this year. For further information on dates of his future grading weekends and of gem and jewellery courses run by Holts Jewellery Academy contact Jenny Palmer on 020 7405 0197.

'D' is for...Gemmology

2006-08-12T16:46:00.000+01:00

'D' Is For ...Gemmology
Readers of this article will know (or should know) that the 'white' diamonds they handle are not truly colourless, but occur in various subtle tints of yellow, brown and grey, ranging from the rarest diamond without any trace of colour to the more common off-colour examples. We can construct a scale of colour quality using letters of the alphabet to designate the colour grades.'D' is applied to describe the rarest "colour" down to S to T colours (we, at the lab, rarely grade diamonds worse than S - why is this?)

'D' colours are different.
Several diamond text books and gem courses insist that diamonds in the 'top' three colours; D E and F, are absolutely colourless and diamond graders can only differentiate them through the degree of apparent transparency seen within the stone. This is not the case. Under standardised viewing conditions, there is a degree of colour apparent in all colour grades. Diamond graders utilise a set of diamond master stones to compare colour and decide the grade of a loose diamond. Each of the master stones represents the colour at the junction between two colour grades. hence the first master stone in the set will be at the border between D and E colour grades. This master stone possesses a very faint hint of colour that experienced diamond graders can readily distinguish. Diamonds having less colour than this master stone will be graded 'D colour'.Various D colour diamonds will have less colour than other diamonds of the same grade. So there exists a subtle range of colour within the D grade, as there is within any other colour grade. This variation of colour within a colour grade becomes wider in each colour grade as one progresses down the colour scale to the off-colours. So diamonds graded D colour may seem similar to most in the gem and jewellery industry, but they can be gemmologically quite different.

Diamond Types
Let's look at the gemmological characteristics of these different D colour diamonds. To understand how diamonds of the same colour grade can be different, we need to look at diamond types. We can divide diamonds into two broad groups gemmologists call 'Type I' and 'Type II' diamonds. It is not possible to distinguish the types using a jeweller's lens - laboratory techniques, such as infra-red spectroscopy, are required. Diamond is made up of carbon. The carbon atoms bond together in a tight strong pattern. In 1959 it was established that the majority (over 99%) of natural diamonds contain sub-microscopic nitrogen as an impurity within this carbon pattern. Thenitrogen atoms replace some of the carbon atoms within the structure. Such diamonds are termed 'Type I'. Those diamonds which do not contain readily detectable nitrogen as an impurity are named 'Type II.'

Type I
Type I diamonds can be classified further into two subgroups; Type Ia and Type Ib diamonds.Type Ia diamonds, believed to be more than 98% of all natural diamonds, contain nitrogen grouped as pairs of atoms ('A-aggregate'); a group of three atoms ('N3 centre'); or a group of four atoms ('B-aggregate'). The A and B aggregates do not absorb visible light so do not affect the colour of the diamond, whereas the N3 centres do absorb visiblelight in the blue end of the spectrum thus giving rise to the pale yellow colour so often seen in diamonds. In general, the greater the concentration of N3 centres, the more intense the yellow colour.
Type Ia diamonds can be further subdivided into three subgroups:Type IaA - in these diamonds, nitrogen is present in the main as A aggregates and they tend not to be fluorescent.Type IaB - in these diamonds, nitrogen is present as predominately B aggregates and these gem can exhibit strong to very strong fluorescence.Type IaAB - in these diamonds, nitrogen is present in the A and B aggregate forms as well as in N3 centres. The N3 centres cause a notable absorption inthe visible region of the spectrum causing pale to intense yellow colours in diamond. These gems may exhibit faint to medium fluorescence.Type Ib diamonds (less than 0.1% of all natural diamonds) contain nitrogen as single atoms within the diamond structure. These nitrogen atoms absorb lightin the blue end of the visible spectrum often giving rise to an intense yellow colour (the true Canary diamonds).

Fluorescence
The bluish hint of colour occasionally shown by many 'colourless' diamonds derives from their fluorescence. If a diamond fluoresces blue under UV light and this glow is strong or very strong in intensity, the diamond will take on a bluish tint in light rich in UV wavelengths, such as bright daylight. Any yellow body colour the diamond possess will be masked by its blue fluorescent glow, so the diamond will appear less yellow (a 'better' colour) in sunlight.This fluorescent effect usually is not considered desirable. D colour diamonds may be fluorescent or not. The A aggregates present in diamond quenches fluorescence so Type IaA diamonds do not fluoresce whereas Type IaB tend to fluoresce strongly.

Type II
Type II diamonds contain nitrogen in such low quantities that its presence is difficult to detect with standard infrared spectroscopy. As with Type I, Type II diamonds can be subdivided.Type IIa diamonds are often absolutely colourless and exhibit an extreme transparency. A number of large historical diamonds, such as the Cullinan and the Koh-i-Noor diamonds, are of type IIa.Those Type II diamonds which conduct electricity due to boron being present as an impurity are termed Type IIb. Most diamonds of this type are blue in colour.

Golconda.
Before the discovery of the South African diamond deposits in the late 1860s and early 1870s there was a grading scale in use describing diamond quality.Better quality diamonds were considered to only come from India so the name Golconda was used for the finest quality of diamonds. Golconda was a fortified town in the Deccan region of India through which for centuries all Indian diamonds, mined further east in the Kollor area, were marketed. Less impressive diamonds were considered to derive from Brazil, where deposits were discovered in the 1720s. Some Brazilian place names, such as Begagem, Canavieras, Diamantinas and Bahias, denoting the areas of mining, were used as names for less impressive quality grades. So the word Golconda was established early on to describe quality diamonds. This term is still occasionally heard to describe highly transparent diamonds without any yellow body colour, or with a bluish tint. Today I see the word abused and used to increase the marketability of some Type IIa diamonds of the finest colour, including D colours, in much the same way as 'Kashmir' and 'Burma' and 'Colombia' origin names are used to increase the value of coloured stones, that may or may not be of the finest quality these place names suggest.

'Blue-White'
In the past, a phrase traditionally used to describe colourless diamonds was 'Blue-white'. This term originally described diamonds that possessed an extraordinary weak blue suffusion and were of the highest degree of rarity. However with time, the phrase became applied erroneously to describe many diamonds that fluoresce blue under UV light. If colourless or near-colourless diamonds fluoresce in sunlight, the faint bluish milkiness mixed with and masked the 'white' of the diamond, hence 'blue-white'. But while colour grading many thousands of diamonds, the laboratory diamond grader occasionally comes across a 'D colour, non-fluorescent diamond that does indeed have an almost imperceptible hint of blue. We do not know the cause of this colour. At the our laboratory in the last year we have seen two of these 'true' blue-white diamonds - one was Type IIa, the other was Type Ia.

HPHT treated diamonds
In previous articles published elsewhere I have referred to the high-pressure, high-temperature (HPHT) process by which light brown type IIa diamonds can be decolorised to improve their colour grades. D colour grades can be accomplished. To identify conclusively such treated diamonds remains a challenge to laboratory gemmologists. All diamonds submitted to the Laboratory are tested for type and any type IIa diamonds are subjected to further rigorous scrutiny.

Summary
D-colour diamonds, rare in nature and difficult for the lay person to distinguish from other top colourless diamond grades, may fall into one ofthe following groups;Type IaA - may have very faint hint of colour with no fluorescenceType IaAB - may have very faint hint of colour, with faint to medium blue fluorescenceType IaB - may have very faint hint of colour, with strong to very strong blue fluorescenceType I Ia - may be absolutely colourless without any fluorescence.Type I Ia - may be a decolorised brown HPHT treated diamond.Type I Ia - may be a gem quality synthetic diamond'True Blue-White' - very faint suffusion of blue, without fluorescence - may not be confined to one diamond type.Every diamond is unique in appearance and quality. This is true within the limits of the D colour grade: D colour diamonds can be gemmologically different.

To test, identify and grade diamonds effectively, an understanding of diamond types and fluorescence is essential.

Natural Pearls

2006-08-06T17:42:00.000+01:00

Our gem lab has examined and reported upon far more numbers of natural pearls during the last twelve months than in any previous year. I cannot recall seeing as many natural pearls submitted for identification in more than twenty years of testing in London. The photo shows a particularly attractive pearl we recently examined. Although most of the natural pearls have been submitted by the four international auction houses in behalf of the vendors, a significant number are being sent by dealers and retailers. I am told the current demand for natural pearls is strong; many good examples being offered in the UK are readily sold to Middle East and Indian buyers.
I would suppose that most readers seldom gain the opportunity to handle natural pearls; the cultured varieties are so common in our industry that the word ‘pearl’ is used (incorrectly) to denote a cultured pearl. It is so important that the retailer and his or her buying client is aware of the differences between the definitions of cultured, imitation and natural pearls and the terms used to describe various pearl types, as recommended by CIBJO, the international jewellery confederation.

So what is a ‘pearl’? Natural pearls are produced purely as an accident by wild oysters and mussels living in seas, rivers or lakes. No human intervention in their growth is involved. The term 'pearl' used without qualification must be applied only to a natural pearl. Owing to the decline in the numbers of pearl- producing molluscs, natural pearls are rarely fished today hence the retail jeweller would only encounter them in old strings of pearls or mounted in antique jewellery. Natural pearls are formed when the wild oyster or mussel is stimulated to produce layer of calcium carbonate, in the form of crystals of calcite and aragonite. These layers are referred to as nacre and are bonded by the occasional layer of a secreted protein called conchiolin, much like mortar bonding the brick layers in the brickwork of a house. The nacre is deposited in a layered and concentric ring pattern to form the pearl. What triggers the oyster to start the production of a pearl is not yet fully understood. Earlier beliefs that the intrusion of a grain of sand or a living parasite into the flesh of the oyster irritated the mollusc to surround the intruder with nacre are being challenged by current theories of the nacre being produced at a time the oyster is in ill health, in a cancer- like state.
A cultured pearl is one produced by the direct intervention of Man in the growth process. There are two types of cultured pearls the jeweller encounters. The first are cultured pearls containing a bead as a nucleus. A spherical bead of shell (mother-of-pearl) or other nucleus material, is implanted by a pearl technician into a farmed bivalve mollusc, usually called an oyster, together with a small piece of flesh from a sacrificed oyster, in order to stimulate the animal to secrete thin layers nacre on to the nucleus The thickness of the nacre, one factor of its quality, is determined principally by the length of time the bead is left in the oyster before being harvested.
The other type of cultured pearl, one that is increasing in quality and popularity, is the cultured pearl lacking a bead nucleus. Pieces of flesh from a sacrificed mussel are inserted into the inner edge of a farmed mussel. Nacre is produced by the mussel so as to surround the inserted flesh which deteriorates forming a small cavity within the cultured pearl. Lacking a bead, these cultured pearls have a greater thickness of nacre than beaded cultured pearls and are usually farmed in freshwater lakes and rivers in Japan and China and are erroneously referred to as ‘freshwater pearls’. These pearls are cultured thus should be described correctly as ‘freshwater cultured pearls’. But whether the mussel grew in freshwater or sea water is not as important as the fact that such ‘pearls’ are cultured. For this reason the Precious Stone Laboratory refers to these ‘pearls’ as ‘non- nucleated cultured pearls’. The American term ‘tissue- nucleated cultured pearl’ is sometimes encountered. Cultured pearls were first produced as a commercial venture in Japan in the 1920s and are today as popular as ever. Once the industry was dominated by Japanese cultivators; now China is a major producer of beaded and non- nucleated cultured pearls and Australia and the Pacific Islands are producers of fine large (over 9 mm.) beaded cultured pearls.
The increasing rarity of natural pearls means they are much sought after. Natural pearls will always be more valuable than cultured pearls of the same size, colour and nacre appearance. Consequently there is a demand for the accurate identification of a single pearl or string of pearls. Only those few dealers in the pearl trade, with a great amount of experience in examining the colour, shape, lustre and surface characteristics of natural pearls, are proficient in identifying them. A string of pearls with similarly sized pearls are more likely to be cultured pearls as it is extremely rare to obtain a number of natural pearls of the same size. Generally speaking, the colours of cultured pearls in a string would be better matched than those in a natural pearl string. If a cultured pearl has a thin ‘skin’ of nacre, rotation of the pearl in front an intense light source may show up, though the nacre, the banded structure of the bead nucleus. This ‘candling’ effect is revealed only if the nacre is sufficiently thin for the light to penetrate the skin. If the beaded cultured pearl is drilled it may be possible to glimpse the demarcation line between the nacre and the bead as a difference in colour and texture, if the drill hole is scrutinised with a 10x lens. Of course, with non- nucleated cultured pearl, no bead is present so a demarcation will not exist.
So how does one tell a natural pearl from a cultured one? The internal structure of each type is of course different. Cutting a natural pearl in half will reveal a concentric ring pattern of nacre much like the skins of an onion or the ring pattern in a tree- trunk. The beaded cultured pearl will reveal the bead nucleus occupying most of the volume of the cultured pearl, with a skin of nacre covering the bead, whereas the non- nucleated cultured pearl will reveal a tiny irregularly shaped cavity in the centre where the tissue implanted to stimulate growth has decayed. Because of these differences are confined to their internal structure one is obliged to take an X-ray photograph, called a radiograph, to show up these structures, much the same way as your doctor or dentist takes an X- ray shot to look inside your internal organs or teeth. At the Precious Stone Laboratory an industrial X-ray generator is used to take radiographs of loose pearls and strings of pearls. The X-ray film is inserted in a black light-proof bag and the pearls to be identified are placed on the bag and exposed to X-rays in a radiation-proof instrument. The exposure times to the X- rays, the X- ray energy selected, the X- ray source-to-film distance and the film processing procedures are controlled precisely in order to develop a set of radiographs that will resolve the fine details of the internal structure of any pearl tested. Pearl identification requires a great many years of experience in examining radiographs of different shapes of natural and cultured pearls - it is not an easy task. Many exposures of the pearl taken from different directions are needed before a pearl can be identified as a natural, beaded cultured or non- nucleated cultured pearl. For these reasons asking your friendly vet or dentist to X- ray your pearl rarely produces an accurate identification.

Padparadscha - what's in that name?

2006-08-06T17:37:00.000+01:00

Several clients have asked me what padparadcha means to me.

The word padparadscha (pronounced by the English as PAD-PA-RAD-SHAH) describes the colour of a most attractive fancy sapphire endowed with both a pink and an orange colour components. Such fancy sapphires are rarely encountered, most examples having been mined in Sri Lanka but recently a limited source has been found in Tanzania. Named originally after a word used in Sri Lanka for the lotus flower bearing such a colour, this appealing description creates difficulty for many in the gem and jewellery industry for the reason fancy sapphires of other colours, such as pure orange sapphires and even dull brown sapphires have had the padparadscha label wrongly attached to them in the hope of promoting an inferior colour of sapphire. It seems that any sapphire with a hint of orange goes by the name of padparadscha. For my gem lab to describe a fancy sapphire with this word, a gem proven not to be heat treated, when viewed ‘face-up,' must display a mixture of both orange and pink colours. The colours will blend in a way in which it is difficult to see where the pink area of the sapphire stops and the orange part begins -- such a true padparadscha colour display is gorgeous to perceive.

Pearls - freshwater or saltwater?

2006-08-06T17:33:00.000+01:00

Q: Is there an easy way to tell the difference between freshwater and saltwater pearls?

A: Members of our industry often are confused with the meaning of the phrase ‘freshwater pearls’ so let’s look at a few pearl definitions. Natural pearls are rarely fished today so the reader would only have the opportunity to handle natural pearls in old strings of pearls and in antique jewellery.. A natural pearl has formed accidentally in wild molluscs without the intervention of Man. Where Man has initiated the growth of ‘pearl’ by implanting either a bead or a piece of organic matter within the productive mollusc, the product is called a cultured pearl. Both wild and cultivated molluscs thrive in either salty marine water or in freshwater rivers and lakes hence natural and cultured pearls obtained from these two water sources can be divided into four groups
1. Molluscs found in marine waters (saltwater) supplied us with most natural pearls, sometimes referred by our industry as ‘oriental pearls’. Few natural pearls are harvested today.
2. Marine waters provides us with cultured pearls containing a bead nucleus e.g. Akoya, South-Sea and Tahiti pearls. These terms should include properly the qualifying word ‘cultured’ as in ‘South-Sea Cultured Pearls’.
3. Freshwater sources, such as some rivers in Europe, provide natural pearls sometimes called river pearls. River pearls have been fished in Scotland.
4. Cultured pearls from freshwater sources are usually non-nucleated cultured pearls and are incorrectly termed ‘freshwater pearls’ by our trade; no mention of their cultivated origin is apparent. China is major supplier of this type of cultured pearls.
So pearls taken from freshwater sources are either natural or cultured hence there is a ambiguity created by the use of the term ‘freshwater pearls’:
There is no simply way of distinguishing natural and cultured pearls from marine and freshwater sources, although an experienced pearl specialists may notice subtle indications in the ‘orient’ and colour of natural and cultured pearls from freshwater sources.
Manganese, a naturally occurring metallic element, is found in greater concentrations in the freshwater of rivers and lakes than in the salty oceans. Molluscs grown in freshwater and the natural and cultured pearls harvested from them are found to contain minute traces of manganese. As manganese fluoresces (glows) under X-rays it is possible using specialized radiographic equipment to differentiate between pearls (both natural and cultured) derived from freshwaters and those taken from the marine sources. However my clients are more interested in my laboratory determining the origin of a pearl (natural or cultured) than its watery source (saltwater or freshwater).

Tanzanite - tough it up.

2006-08-05T09:19:00.000+01:00

I am seeing more tanzanite submitted to our lab for verification. It can be a nice looking stone but susceptible to cracking. Here's what I replied to a query in the UK trade magazine about tanzanite's hardness

"Tanzanite is the transparent blue-violet variety of the gem zoisite. It is mined as crystals of mostly brownish-green in colour: heat treatment produces its attractive colour comparable to the finest blues of sapphire. Indeed tanzanite is thought by some to be a less expensive substitute for sapphire. It’s a ‘new’ gemstone as it was only discovered in the 1970s in Tanzania in East Africa
The hardness of a gem can be defined simply as its resistance to abrasion and scratching. Gemmologists refer to the Mohs scale of hardness, a numerical order with diamond, the hardest gem known, at 10, sapphire at 9 and tanzanite is between 6 and 7. The surfaces of gems of hardness 7 or less, such as tanzanite, will eventually be abraded by exposure to daily wear and tear. However it is the toughness of tanzanite that should be understood and explained to consumers. Toughness, not to be confused with hardness, is the term gemmologists use to describe the resistance of a gem to breaking, cracking or chipping. It is a measure of how brittle a gem is; its ability to withstand mechanical stress, such as experienced from a blow or sharp knock. Even diamond is rather brittle; witness the chipped girdles commonly seen on antique cuts. Jadeite and agate are extremely tough gems whereas tanzanite lacks toughness. The gem is likely to shatter if exposed to ultrasonic cleaning and I have seen more than a few examples that have cracked during re-polishing. It is best to point out to a prospective purchaser of tanzanite these aspects of care needed to enjoy this attractive gem."