Oct 312012

This biannual conference is hosted by Richard Drucker and his associates at Gemworld International and was attended by delegates from eight countries.  Among the attendees were AIJV members from Canada, Scotland and the USA.

The weekend started on the Friday night with a “Meet and Greet” at the Hotel’s Private Dining Room. It was a time to renew old acquaintances and meet new people. Conversation flowed.

Alan Hodgkinson – Intriguing Observations and Experiences with Gemstones

Alan HodgkinsonSaturday started with a continental breakfast and the day of lectures started at 8.45am with Alan Hodgkinson, President of the Scottish Gemmological Association.  His talk was about what gemmologists see when looking for evidence of treatments and how they occur.  An example of neutron changing the colour of diamond is that the colour changes through the diamond, not just under the surface.  Also, if you have a diamond that looks black to the eye it may look green in the fibre optic-this is a sign of neutron induced colour.  Don’t forget to look for little details when looking for treatments such as flux on the corner of a facet on the corundum that may not be polished off, spotted by observing the lustre differences.

Alan gave another great tip: When you are trying to get a spot RI on a “reluctant” gemstone, try shining the fibre optic through the stone on the prism, forcing the light to be reversed through the refractometer and very often revealing a previously invisible reading. There were many other tips and intrigues given to us from his vast experience.

Dr. Cigdem Lule – What’s in a Name: Gem Terminology.

DR. Cigdem LuleCigdem Lule was next with an interesting talk concerning gemstone trade terminology and advocating that we should have clear terminology within the industry that also makes sense to our clients.  There are many things that affect what terms we use when discussing gems, such as the romance to sell the stone, basic descriptions, traditional gems with modern terminology, branded gems, etc.  The other aspect of this discussion is that not all words have the same meaning in all languages.  Do we need terminology for the industry and another for selling to consumer?  Should we be calling something man-made? Synthetic? lab grown?And what about the terms treated verses enhanced?  Should natural continue to be used if gemstone is treated?

There were many more examples of areas that we have not defined as an industry and the language we all should be using.  These are areas that we as an industry should be looking at and dealing with ourselves, or are we going to leave it to the Internet?  Maybe we need to go back to semantics and develop a gem glossary?


Shane McClure – Quantification of Flux-assisted Healing in Ruby

Shane McClureAfter a coffee break, Shane McClure from the GIA gave a talk outlining the GIA’s approach to assessing this type of treatment.  He explained that this form of enhancement was carried out on Mong Hsu rubies due to the blue core and the feathers that are typically present in this material   This process is also applied to sapphires.

Shane showed some great photos of what was considered “Not Treated” (NTE) through a quantifying system of TE1 –TE5 with TE5 being significant treatment.  It is important to remember is this process is not about clarifying but about stabilizing the stone.  The question is … would this stone be stable if not healed?  The system looks at the amount of residue present. This would have been originally expressed as ‘minor, moderate and significant’. Now the scale NTE-TE5 is used. This is a subjective system not  exclusively about clarity, in the traditional sense.  More discussion is taking place regarding how many levels are needed to improve this system.


Richard Drucker – Pricing Corundum Treatments

Richard DruckerRichard gave a short 10 minute presentation about pricing with regard to heat treated, heat+flux, diffusion treated gems and also glass composite products.

A quote from Richard that we would all do well to think about …  “the longer treatments exist, the more acceptable they become, and inaccurate disclosure will destroy consumer confidence“.


Stuart Robertson – Retail Opportunities, Pricing Unusual Gems

Stuart RobertsonStuart Robertson from Gemworld International followed with an observation on the movements in the conditions surrounding marketing gemstones. As retailers, Stuart notes, in this economy there are too many similar stores with the same inventory mix.  As the economy diminishes buying power, the trend is to lower retail price points.

We also see the use of alternative metals in fine jewellery due to the precious metals pricing.  Maybe retailers should be introducing their clients to alternatives such as all the varieties of Quartz.  They have the fashion colours and the added bonus of appearance and popularity.  What about Sphene in a warm green at $60-$150 for a 1-4carat stone?  Scapolite is selling in the 1-3 carat size for $50-$125. Other ideas Stuart offered was Diopside, Danburite, Zircon, faceted transparent Rhodocrosite and Malawi Sapphire. Bringing these stones to your client might be the edge you need over your competitor.


Some of the presenters at the WOGC lll

As you can see this was a fact-filled morning. Yes … all these talks before lunch!


Robert Weldon – Fortune and Fortuity in the Quest for Brazil’s Hidden Emeralds

Robert WeldonWe started our Saturday afternoon with a historic adventure with Robert Weldon from the GIA taking the lead. Robert presented an  interesting talk about the Bandeirantes (Portuguese flag bearers) from the 1600’s and their search for gems, minerals and slaves in Brazil.  The quest was to find emeralds as the Inca king at the time had a pendant with an Emerald.  They found tourmaline but never emerald.

The talk covered the hardship of the search as well as the gems found and of course about 40 years ago the Belmont Mine in Nova Era was discovered and has more emeralds than any other mine in South America.


Jack Ogden – Sunlight and Icicles—the History of Diamond Cutting and Assessment

Jack Ogden of Gem-A followed with his talk where we saw drill holes in beads and engraving on cameos, all from the 6th and 7th century, evidence that a diamond drill was being used.  We saw slides of a cut diamond ring from 1477, diamonds in Brazil in 1730, India 1730-1870 and South Africa 1870.

There are Indian works that show a form of diamond grading from 1000 years ago. They looked at size, perfection of shape, dispersion, colour, lack of scratches and lack of internal features. Does sound familiar doesn’t it?


Mary Johnson – Quality Traits of Minerals: Value Factors

Brazilian TourmalineWhat about minerals?   Well, they had their place at this conference too with a talk given by Mary Johnson.  It was a fascinating talk on how to look at minerals and that it is the 4Ss and the 2Cs that matter when grading minerals- Self, Shape, Source, Size, Colour and Clarity. What is it?  What species?  What is the chemical and atomic structure?  Where is it found? Are the crystal faces sharp and clear? Is the crystal in host rock?  Is the colour pure? Is it gem quality for clarity or not?

Sometimes the material is good for a mineral specimen but not for a gem specimen.


Stuart Robertson and Dr. Cigdem Lule – Evaluating Fancy colour Diamonds

Stuart and Cigdem joined forces for the last talk of the day. They discussed the things that we look at when grading coloured diamonds such as needing to understand the 27 hues for fancy coloured, that they are graded face up, that saturated and darker colours are rarer and more valuable.  There is an article in 1988 Gems and Gemmology about this subject.

Noted were the modifiers usually present within fancy coloured diamonds. Blue can have a grey modifier. Yellow can have brown, orange and green modifiers.  A warm yellow would have an orange modifying colour, where as a cool yellow colour would have a green modifier. Pinks are more commonly lighter and can have blue, grey, orange and purple modifiers.  Also Gems and Gemmology in 2008 had grading charts. Stuart and Cigdem talked about rarity versus market rarity and the colour rank by value. A great talk to finish the first day of lectures.


Chicago Police & Fire Pipes and Drums

The lectures might have ended for the day but the fun and food were just beginning.  A cocktail party of complimentary food and drinks was then held for all delegates.  A surprise visit by some members of the Chicago Police and Fire Pipes and Drums was a great hit with the crowd.  It was even nicer when they stayed to eat and drink and play some more during the 2 hour party.  Alan Hodgkinson was on hand in his full Highland Dress to thank and “pay the pipers”.


Alan Hodgkinson – Gemmology in Action

Sunday started with Part II of Alan Hodgkinson’s talk on Gemmology in Action. This time Alan gave us his insight into gems that are above the refractometer limit.  He also talked about how to use the B/G ratio for identification or elimination—sometimes it is good to be able to say what it is not in order to go forward to identification. Visual Optics, Alan tells us, was started back in 1887 by Prof Louis Dieulafait.

I always find Alan inspiring.  He reminds us to practice and play with identification this way, so not only will you get better but it is amazing what you will learn.  I think that as gemmologists we sometimes get so busy in what we are paid to do that we forget why we became gemmologists and Alan always reminds us.


Gary Roskin – Diamond Grading Standards

Gary Roskin gave us a talk on Diamond Grading Standards.  As we know all labs can have their own standards but we should all be using the same technique to at least stay consistent in our standards.  The practice when looking at colourless diamond mounted is to grade the colour from the side, but coloured diamonds must be done face up all the time.  He also spoke about the necessity of upgrading equipment to keep up with the improvements to them.  He discussed inclusions, their locations and how this impacts the grade. Gary also talked about techniques for tilting the diamond to see inclusions.

As valuers, we need to compare the laboratory report to the diamond, checking that the identification number is correct and that the features shown in the plot diagram match the diamond we have in our hand. A very informative talk.


Dr. John Emmett – The colours of Corundum: A Search for the Soul of a Padparadacha

John Emmett’s talk was all about how stones are coloured and what needs to happen at the atomic level to induce colour.  He talked about what was required to measure this accurately and what corresponding effects can be seen in a spectrometer. What makes colour? Elements mixing and blending? Ions?

Chromium, Iron, Iron + titanium, Iron-hole, Chromium-hole are what give colour in Corundum. I must admit that although I found this talk fascinating and understand why it is important research, it was at times a bit beyond my scientific recollection and knowledge. However, Dr. Emmett is always an interesting speaker and forces me to broaden my knowledge.


Doug Hucker –  Federal Trade Commission

After lunch, Doug Hucker of the AGTA, gave a 15 minute update from the Federal Trade Commission‘s  guidelines concerning pearls, gems and metals. The FTC stress that the client is the consumer and not the industry. Revisions are continuing to be done to the guidelines and the website link to the current status is:


Shane McClure – Emerald Treatment Levels

Shane McClure talked about Emeralds today and their gem treatment levels. The GIA’s quantification of Emerald clarity enhancement was explained.

The scale used by the GIA is F1 (minor), F2 (moderate) and F3 (significant). In today’s market we don’t always see the flash effect any more, so finding the filler can be a problem.  Shane went on to list the factors involved, including: the number of fractures, their location, how well filled they are and considerations of polymerized fillers and heavily included stones.  His last note was – beware of it being more than a clarity enhancement … it could be held together with resin.  An informative and timely talk, since we are seeing more of the resin/emeralds showing up on the market.


Richard Drucker – Emerald Pricing

Richard Drucker gave one of his quick talks about pricing Emeralds. Today we are pricing emeralds at the moderate clarity level as the norm and then premium or discounts applied from there.

Consumers want to know whether the treatment stable and reasonably permanent.


Henry Kennedy – Romancing the Stone

A fun talk was given by Henry.  He talked about his mining experience and mining in general for the last 30-50 year in Brazil.

A flamboyant speaker Henry showed the importance of branding yourself and letting yourself be known.  He uses his hat as his brand—what do you use?



Richard Drucker – Labs and their affect on prices

SSEF Grading ReportsRichard Drucker once again did a comparison of labs for us. This time he compared some US labs and how they impacted the market price of the diamond cited in the report. It was noted that GIA was closest to the Gem Guide for a diamond of apprx 1-1.19 ct ( sample stones –  G, VS2 with very good proportions). Progressively discounted were IGI, EGL-US, EGL-SA.  Although, he demonstrated that the order of decrease had not changed in two years since the last study, the levels of discounts had changed a significant amount. It is something to be aware of when your customer wonders why the pricing of the stone is so different from your report to a lab report.



Lecture Hall at WOGClll

This was a great weekend filled with interesting lectures, fun times with old friends, making new friends and yes, even the tornado warning could not dampen the enthusiasm in the room and I will look forward to going back in 2014!


Disclaimer – The AIJV blog is authored by a selection of AIJV members and guests specifically to be able present many different viewpoints on a large variety of subjects. The opinons expressed by the authors are not necessarily those of the AIJV.

Photo Credits :
Chicago Skyline – Intercontinental Hotels and Resorts
Photographs of the Speakers, Lecture Hall and Band – Gemworld International Inc.
Robert Weldon – Women’s Jewelry Association
Tourmaline – wellarrangedmolecules.com
Emerald – Tino Hammid Photography
Zircon and Lithium Niobate dispersed spectra – Scottish Gemmological Association
Grading Reports – SSEF (SSEF’s reports were not discussed during this presentation)
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Karen Howard

Karen Howard is the principal of KC Appraisals, an AIJV member in Guelph, Canada. Karen has been a tutor for the Canadian Gemmological Association since 1990 and a past member of their Board of Directors. Karen's own Blog can be found here: https://karensappraising.wordpress.com/ Karen Howard est le manager de KC évaluations et membre de l'AIJV à Guelph au Canada. Elle enseigne pour l'Association canadienne de gemmologie depuis 1990 et est ancien membre de leur conseil d'administration. Son Blog se trouve ici: https://karensappraising.wordpress.com/

  5 Responses to “World of Gems Conference III in Chicago – Review”

  1. Karen,
    thanks for a useful review. Looks like the ‘grading’ of ruby and emerald fillers is now well established. Anything mentioned on the low temperature vs. high-temperature of sapphire debate?
    Kind regards

    • HI Eric
      Thank you for the kind words. At least we know the fillers are being given guidelines that we as appraisers will be able to use to help with valuation as we become more informed about the research and guides. I did not hear much being talked about with regards to the sapphire debate.
      I will be glad to keep you informed on that issue as I am sure you will do the same for me.

  2. This looks like a fabulous conference, I just wish Australia wasn’t so far away from the rest of you. I will have to try to make some time to attend hopefully in the near future.

    • Hi Kym: We wish it wasn’t so far away either, it would be nice to meet you in person. I am glad you enjoyed the review. It was an informative, diverse conference.

  3. It is rally very nice to listen the geniuses of the gem and jewelry industry. I wish I could be present there while they were in the conference. I hope I could be there next time.
    Uday S Dey

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