E-Newsletter Plus 2010
For fifteen years EGM's Gemmology 1 course notes have described spinel as underestimated, underappreciated and historically considered a marginal gemstone despite its tremendous beauty and durability. Those days may be over with ample evidence found at the 2010
In the early 2000’s the Tucson Gem Show had one exhibitor specializing in spinel. By 2005 a few more gem dealers were starting to display and sell spinel and 2010 saw a veritable explosion of dealers showcasing this gem. Buyers and browsers alike were treated to a wealth of options in a variety of colours: red, pink, mauve, and blue ranging from pastel hues to intensely saturated specimens. Spinels from
Hours could be spent selecting the perfect stone from amongst hundreds of options or just admiring the display cabinets of dealers like Henn GmbH in the Idar Oberstein pavilion whose offerings included a spectacular suite of five vivid red spinels from 20 cts to over 40 cts as well as several other fine specimens and imaginative sculptures including a life-size lobster carved out of ruby with gold legs and a beryl crystal partially coated in gold with a texture reminiscent of the surface markings seen on rough beryl!
As part of the AGTA’s seminar series which runs in conjunction with the show, Edward Boehm of Rare Source spoke about his early introduction to spinel as he traveled in Burma with his grandfather, well known gemmologist Edward Gubelin, in a lecture entitled “Spinel: A Royal Gem”.
He reminded attendees that spinel has been around for centuries and despite our ancestors ability to distinguish between ruby, red spinel and garnets they were all grouped under the name ‘carbuncles’. Crown jewels from many countries prominently display spinels. One of the best-known examples is the Black Prince ‘Ruby’ which is a 170 cts spinel in the crown of Queen Elizabeth II of
Rubies are very rarely found in large sizes and a 15 cts ruby is considered a museum piece. These large royal ‘rubies’ are spinels that probably came from Badakshan, the region known today as
2010 appears to be the dawning of a new age for spinel and may well mark the beginning of an era of unprecedented popularity for this gem. Available in a wide range of appealing colours of varying intensities, with a hardness of 8 on the Mohs scale, very resistant and, for the moment at least, untreated spinel is poised to be a sensation. An unfortunate consequence of its new popularity is the rise of flux melt synthetic spinels seen on the market. These types of synthetic stones can be very difficult to detect!
The histories and destinies of ruby and spinel are probably so intimately linked because they share many common features. The two are often found side by side in calcite rich environments. They are both aluminum oxides (with magnesium in the case of spinel) coloured by chromium. They can both have healing fissures and crystal inclusions. In nature, spinel forms first until there is no magnesium left and then the remaining aluminum and oxygen form ruby… almost like a by-product!
Already certain spinels are more rare and sought after by collectors and consumers. Notably the exceptionally intense pink spinel from Namya an area near Mogok in Burma and the unique blues from Sri Lanka coloured by iron and rarely by iron and cobalt.
Also new in
The rose cut, seen in sapphires and other stones. A great way to make use of flat shaped rough and also gives the look of a larger stone with a smaller price per carat.
Truly phenomenal Ethiopian opals from a new deposit in Wollo. Visit the Opalinda web site to see some examples. www.opalinda.com
Renee Newmann has a new book: Exotic Gems, Volume 1, available at EGM.
Bracelets in round and rope shapes made of thin wires of 18k gold that allows them to be stretchy like an elastic.
Some very interesting clarification of terms regarding freshwater cultured pearls provided by Elizabeth Strack, author of the pearl ‘bible’ called Pearls
An ikecho pearl is a pearls obtained from the insertion of a nucleus into the gonad.
A coin pearl is obtained by insertion of a flat disc like nucleus into the pearl sac after the harvesting of another pearl.
A fireball pearl is obtained by inserting a round nucleus into the pearl sac after the harvesting of another pearl.
A petal pearl is obtained by replacing the mollusks in the water after harvesting coin pearls.
A new soufflee pearl is obtained by inserting a round piece of dried dung (yes you read that correctly) into the pearl sac after the first harvest. The dung is dissolved and the resulting pearl is hollow and is seen in sizes of 13mm to 20mm.
The prices for Tahitian and
Both events were held at the well-appointed McGill Faculty Club on the McGill University campus in the heart of Montreal.
EGM 15th ANNIVERSARY
Thanks to our generous sponsors and donors there were many great gifts and door prizes awaiting the gala dinner attendees. A short film documenting the first 15 years of the EGM showing interviews with students both past and present was also shown during the dinner.
Jeremy Sawas and Alisson Lemaire hosted the evening. Close to 150 people gathered for the evening.
The guests of honour including speakers (named later) and VIP guests Richard Drucker publisher of GemGuide, Jack Ogden CEO of Gem-A, and Bushan Vora President of the Diamond Bourse of Canada, were introduced and accompanied to their tables by EGM students.
The 150 guests were thrilled to have the opportunity to catch up with old friends, make new acquaintances, and network in a friendly and festive atmosphere.
Sunday saw the speakers giving their presentations in both English and French at different times throughout the day. Instead of having a general theme for the conference, the organizing committee made a conscious decision to invite bilingual speakers whose diverse areas of expertise represented current topics of interest in the gemmological world.
Three of the presentations addressed three very different aspects of diamonds while the other two speakers focused on coloured stones. This very informative day was capped off with a hands-on session where delegates were invited to observe specimens of treated corundum.
The Renard Mine, Quebec’s First Diamond Mine. Presented by Ghislain Poirier
One of the most anticipated presentations was that of Mr. Ghislain Poirier, vice-president of public relations for Stornoway Diamond Corporation. Mr. Poirier holds a degree in geological engineering form the University of Laval and a Masters degree in Economic Geology from UQAM.
Stornoway Diamond Corporation is a Canadian mining company specializing in diamond exploration and mining. The Renard mine represents the efforts of a joint venture, which began in 1996 between Stornoway and Quebec based company Soquem.
The Renard mine is located in the James Bay region of Quebec 350 kilometers northeast of Chibougamou and approximately 150 km south of LG4 on the banks of lake Lagopede.
Mr. Poirier noted that there are very few new diamond mines around the world. Although the economic crisis of 2009 caused a decline in the diamond market, all indications suggest that as of 2011 the current supply of diamonds will remain stable while demand will increase. Thus the discovery and opening of new mines will play an important role in the diamond market.
Mr. Poirier discussed how diamonds are transported to the Earth’s surface by volcanic eruptions resulting in volcanic pipes opening into a crater at the surface. The magma transporting diamonds to the surface travels at incredible speeds traversing the depth of the Earth’s crust in under an hour. Not all volcanic pipes are diamond bearing and the Renard mine is particularly interesting because it has many diamantiferous pipes.
The first diamond bearing pipes were discovered in 2001 and as of 2010 there are six diamantiferous pipes considered viable with a projected productivity period of 25 years. Based on sample studies, the estimated value per carat is $117.00 US.
Mr. Poirier presented very interesting data that demonstrates an uncommon positive correlation between the size and the quality of diamonds mined at Renard: the larger the diamonds the higher the quality.
Although the final decision concerning the opening of the mine will not be made until the end of 2011, the Transport Minister of Quebec has already approved in principle a 268 km extension of highway 167. All parties concerned are hoping to reach an agreement with Hydro-Quebec that will see existing power lines extended to include the mine site. Negotiators have also been involved in talks with local aboriginal communities to determine the role they will play in the development of the site.
Mr. Poirier was optimistic that the Renard mine will be a world-class operation establishing Quebec as a diamond producer.
Pink Diamonds from the Argyle Mine, Francine Payette
Originally from Quebec and now living in Perth Australia, Francine Payette holds a B.Sc. and Masters degree in Geology from the University of Montreal. She also holds Diplomas in Gemmology from both Gem-A and the Australian Gemmological Association. Mrs. Payette teaches gemmology and is the editor in chief of the Australian Gemmological Association’s publication.
The Argyle mine which is located in northern Australia and has produced over 750 million carats of diamonds since its’ opening in 1983 is slated to close in 2018. Although its’ production has always been high, some 35 million carats per year, only 5% are of gem quality. Of that 5%, 75% are brown, 20% colourless or grey, and 5% are yellow. Less than 0.01% are pink and even fewer are blue, violet, or green.
Mrs. Payette presented information about the cause of the pink and brown colours in diamonds from the Argyle mine based on a new model of research using results from studies of HPHT treated stones.
Every year the Argyle mine holds an invitation only pink diamond tender where it sells between 40 – 60 of the mine’s best stones. Given the planned closure of Argyle, it is safe to say that pink diamonds will soon become even more scarce unless a new source in discovered.
The Journey of Light in Diamonds, Sir Gabriel Tolkowsky
Sir Gabriel Tolkowsky is the sixth generation of a legendary family closely associated with diamonds. It was his Great Uncle, Marcel Tolkowsky, who, in 1919, defined and set the parameters of the perfect round brilliant cut. Sir Tolkowsky has made his own remarkable contributions to the world of diamonds and is perhaps best known for having cut some of the world’s largest diamonds including the Centenary diamond. The planning, design, and execution of the freestyle cut for the Centenary, a 273.88 carat flawless D colour, took three years to complete.
Sir Gabriel Tolkowsky’s presentation captivated the hearts and minds of his audience. Instead of focusing on numbers, percentages, precise angles, and scientific data about the trajectory of light through diamond material, which one might expect from a man who is undoubtedly the finest diamond cutter of our times, Sir Gabriel Tolkowsky shared another side of himself with his audience. He became simply “Gabi” the champion of beauty, a passionate connoisseur who deeply appreciates the unique and intrinsic beauty of all diamonds.
Attendees were treated to a demonstration using music created by two seemingly identical diamonds, both cut by Sir Tolkowsky. The music, created using the interaction of light with each stone, was different for each diamond despite the fact that they both had identical cuts. Sir Tolkowsky used this demonstration to illustrate his position that the beauty of each stone, and everything we consider beautiful, is unique. There are some 10 000 proud diamond owners around the world who have had the musical identity of their diamonds recorded by Sir Tolkowsky.
Pictures cannot do justice to such an enthusiastic and inspired presentation, as those fortunate enough to attend will tell you: ‘you just had to be there.’
Current Corundum Treatments, Dr Laurent Massi
Dr. Laurent Massi holds a PhD in physics from the University of Nantes and has taught gemmology in France and Thailand. He was head of the research laboratory of the Asian Institute of Gemological Sciences (AIGS). Based in Thailand, Dr. Massi currently works as a consultnt. His presentation focused on current corundum treatments being done in Thailand.
Dr. Massi demonstrated a link between the predominance of certain treatments and the discoveries of new corundum deposits in locations such as Tanzania, Mozambique, and Madagascar. His presentation outlined the major types of treatments performed on corundum: heating without additives, and heating with additives: a)borax; b) glass with or without lead; heat and surface diffusion with colouring elements and heat and lattice diffusion with beryllium.
Late in 2004, much of the rough ruby from Madagascar was being treated with lead glass. The rough was mostly pale pink and nearly opaque before treatment and was rendered significantly more red and more transparent by this treatment. The treatment was easily identifiable by the presence of bubbles and blue reflections.
In 2009, the treatment was refined and large quantities of stones from newer deposits in Mozambique were being treated. These treated stones showed none of the telltale bubbles and blue ‘flashes’ seen in the Madagascar stones from just a few years earlier making detection impossible without the use of advanced testing such as EDXRF. This same period saw an influx of treated star corundum in all colours including black, pink and red that had been treated at low temperatures making visual detection very difficult. Also appearing around this time were “composite” rubies which are defined as “stones comprising two or more pieces of ruby held together by tinted glass”.
Since 2005, besides the iron and titanium diffusion treatment of sapphires, treaters in Bangkok started treating large quantities of sapphires, including some very big stones, with beryllium only ‘bulk’ diffusion. Detection of this treatment is possible only if certain characteristic inclusions are present. In stones without inclusions advanced laboratory testing is required to positively identify the treatment. (Dr. Massi noted that it is important to remember that some untreated natural sapphires contain beryllium.)
Staying abreast of new treatments and detection methods is especially important because most of these treatments (especially the element rich glass fracture filling) will negatively affect the stone’s durability. Special care is required when using ultrasonic cleaners, setting or repairing, and even sometimes when wearing these treated stones.
Even though many of today’s corundum treatments require advanced technology to detect, Dr. Massi emphasized that nothing can replace careful observation and solid training and experience.
Ethical Mining and Fair Trade Certification, Jean-Claude Michelou
Jen-Claude Michelou is involved in many aspect of the gem world. Based in Bogota, Colombia where he is involved in the trading, cutting and exportation of emeralds, he is also the vice-president of the International Coloured Gemstones Association (ICA). He also consults with the Nigerian government about issues surrounding the gem trade as part of a World Bank project dedicated to establishing sustainable mining resources.
Mr. Michelou addressed a very current topic that affects all of us in the industry, the ethical mining of coloured gemstones and the need for certification. We are grateful to Mr. Michelou for making his entire power point presentation available to our readers.
In the presentation you will find definitions of fair trade practices and plans for implementing certification protocols for coloured gems. 80% of the world’s coloured gems are produced by artisinal small scale mining operations that face many challenges including health risks, environmental concerns and traceability.
A working committee has been formed to establish criteria for ethical practices and traceability in participating countries. Mr. Michelou heads this committee which included many trade organizations, NGOs, local communities and retail establishments. For a complete list of participating parties and countries see Mr. Michlou’s power point presentation.
JEWELLERY DESIGN CONTEST
In honour of its’ 15th anniversary, EGM held a jewellery design competition inviting submissions from students studying jewellery arts at schools associated with EGM. The grand prize was a selection of stones including two tanzanites (1.18 ct and 2.12 ct) and five small Sri Lankan moonstones.
The jewellery arts department at the Centre professionel Maurice-Barbeau in Quebec submitted the most entries. A jury of professionals consisting of Annik Lucier, designer; Lynn Legare, jeweller; Pius Kaufmann, owner and designer for Kaufmann de Suisse selected three finalists. The three talented finalists were: Valerie Dion (pictured here on left) and Anca Raluca (on right) both from the Maurice Barbeau school in Quebec, and Anne-Marie Legault from the Montreal School of Jewellery.
The organizing comitee : Chandra Horn, MA, FGA, MV, assistée de Odile Civitello, GG, FGA, CAP et Jacinthe Emond, FGA, MV
The three finalists had their designs displayed at the gala evening celebrating EGM’s 15th anniversary. The winner was selected by the guests in attendance who voted for their favorite design. Anne-Marie Legault’s design came out on top with Valerie Dion a close second.
That night proved to be very good for Anne-Marie Legault as she was also the lucky winner of one of the most coveted door prizes available: a 0.35ct ‘gabrielle’ cut diamond which was even presented by the creator of this fantasy cut, Sir Gabriel Tolkowsy.
We would like to thank our sponsors and donors for their support.
T.I.G. and Gabrielle Diamonds
Diamond Bourse of Canada