ISSN 0846-3611 GEMMOLOGY CANADA – Wolf Kuehn, F.G.G., F.G.A., Editor
From the Editor:
Since my return from a very successful AGTA GemFair in Tucson, Arizona we have been busy shipping orders and answering questions about our courses and products. I am happy to report that the work for the GL Gem Raman has now been completed and the first units are ready for shipment.
The Canadian Institute of Gemmology will be exhibiting at the upcoming BC Gem and Mineral show (see below). At the C.I.G. booth the GL Gem Spectrometer and the GL Gem Raman will be demonstrated to both dealers and visitors; we also have new books on display and specials on gem testing equipment are available. Please drop by if you are in the area.
I will be travelling to Europe to attend the Geo-Raman in Nancy, France (June 11-13). Before and after I am available for any meetings, demos or talks to groups interested in our line of spectrometers and any training sessions; please contact me.
We have started revamping our website. The interface is being upgraded using the Genesis Framework which will give us the flexibility and power to develop a modern and secure web environment.
BC Gem & Mineral Show – April 13, 14 & 15
Ag-Rec Building, Central Fraser Valley Fairgrounds, 32470 – Haida Drive, Abbotsford, British Columbia
Admission: Adults – $6.00, Students (6 – 17) – $2.00, Under 6 (accompanied by an adult) – Free
Learn about mining from Britannia Mine Museum and Sego Resources, see the beauty created by Clayburn Copperworks, Beads, Crystals, Minerals, Gifts & supplies for the lapidary hobby. Many Club Displays, Demonstrations, Grab Bags, Children’s Creative Workshop, Gold Panning & Door Prizes.
C.I.G. Advisory Board Member Charles Lewton-Brain Receives Award
A Calgary goldsmith, artist and educator, renowned internationally for his innovative work in the world of jewellery, will be presented with a 2012 Governor General’s Award in Visual and Media Arts at the end of March. Charles Lewton-Brain, 55, longtime teacher in th jewellery and metals program at the Alberta College of Art& Design (ACAD) will receive the Saidye Brongman Award at the official awards ceremony on March 28 at Ottawa’s Rideau Hall. Along with a special issue medallion by the Royal Canadian Mint, Lewton-Brain and his fellow recipients will be awarded with $25,000.
The London, England born goldsmith has dedicated his life to the art of jewellery since being introduced to the craft as a teenager while in the American southwest. It was a girlfriend’s mother, a dealer of Native American jewellery, who got him hooked, he says, when she taught him how to grind turquoise by hand “the old fashioned way, using a grindstone.”
Studying jewellery and metals at the Nova Scotia College of Art Design and then traveling around the world to learn from some of the top goldsmiths on the planet, Lewton-Brain arrived in Calgary in 1986 to begin his illustrious career at ACAD. He first found himself in the international spotlight in the late ‘80s for inventing a technique called foldforming, which uses simple hand tools to rapidly shape sheet metal. Lewton-Brain has also made a substantial impact as an educator. In addition to his work at ACAD he started his own publishing company, Brain Press, through which he’s published “eight books and about 25 papers,” he says. He also co-founded Ganoskin.com, the world’s largest free online resource for jewellers.
Emerald, Sapphire, Diamond Coated CZ
At the booth of Anupam Gems located in the GJX tent during the Tucson gem shows we were introduced to several new “man-made” gemstones (see advertisement).
We purchased a very nice looking .80 ct emerald, a 2.58 ct deep blue sapphire and a .10 ct sparkling diamond simulant.
The emerald was disclosed as “recrystallized” in a proprietary process, the sapphire as “diffusion treated” and the “Diamondspark” as a diamond coated cubic zirconia (“Diamond Nano Coated CZ from Japan”). We tested the samples with regular gem testing tools, the GL Gem Spectrometer and the GL Gem Raman.
Under the microscope the “Diamondspark” looked very much like diamond but tested CZ with a diamond tester.
With the GL Gem Raman we obtained the typical spectrum for cubic zirconia.
The very nice looking 2.58 ct blue sapphire was disclosed as diffusion treated.
At their website, however, listed are re-crystallized sapphires “Made from 100 % natural stone in Japan using nano tech”.
Under the microscope and in immersion we could not find any typical pattern pointing to surface diffusion treatment. The stone was flawless under 40x magnification; if the sapphire had been re-crystallized one would expect some occurrence of “melting” features or gas bubbles which are difficult to keep out.
While untreated sapphires rarely exhibit fluorescence, stones exposed to high-temperature heat treatment and synthetic (flame fusion) sapphires do; read the article “Heat Seeker” by R W Hughes/J L Emmett. Our sapphire became fluorescent when irradiated by the laser beam in the Raman unit.
GIT reported an “Update on Titanium diffused Sapphire” in 2010 where colour patching was more difficult to detect.
Using the GL Gem Spectrometer we obtained similar absorption curves on record for natural (untreated, unheated) Ceylon sapphire; the Raman spectrum was affected by the fluorescence of the stone and therefore of limited value.
In summary the information provided by the seller was confusing. The high price for the emerald and the very low price/ct paid for the sapphire cannot be explained either. In smaller sizes these stones could be cause of concern as they might be difficult to identify and further studies are necessary; if they are bigger (and the seller had fairly large stones for sale) the lack of any inclusions should ring the alarm bell.
Untreated Natural [name of gemstone]
Walking through the isles of the AGTA GemFair I noticed many signs stating “UNHEATED”; it appears to be a new selling strategy to avoid any disclosure that perhaps this “unheated ruby or sapphire” may have been treated by some other means. If that’s the case it still does not make the gemstone a natural gemstone. An untreated gemstone is a natural gemstone (by definition coming out of the ground). A ruby is a “natural” gemstone unless it is heat-treated, filled, or enhanced by other means and disclosed accordingly.
There are very few “untreated” rubies and sapphires; most of these rubies, emeralds, sapphires (just to name a few of the more popular gems) have been modified, manipulated or “man-made”. Most consumers have no idea what these stones looked like when they came out of the ground. If they did and realized how much the treated gemstone will cost them perhaps they started looking for alternatives. There are very nice man-made gemstones which are available at reasonable prices; they are more durable and can look very deceiving!
I am occasionally wearing a small 14k yellow gold ring set with a very attractive Kashan synthetic ruby to my gem identification classes. Most students believe it is the real thing until I have them check the stone under the microscope. I also have a ring set with a large chrysoprase cabochon which is often mistaken for jadeite.
GL Gem Raman Ready for Delivery
I have almost stopped using the traditional testing tools (with the exception of the microscope) as the Raman can handle most gem materials (including those set in jewellery) as long as they fit in the sampling stage (max. 90 x 90 x 50 mm). If the sample is larger the observation lid needs to be kept open and safety goggles must be worn during the testing.
It takes less than 2 minutes to obtain a spectrum. It may take a bit longer if the sample is fluorescent as the laser intensity has to be reduced and some parameters in the GLGemRaman program adjusted; if the fluorescence is too strong the GL Gem Spectrometer will be helpful.
The GL Gem Raman is an ideal addition to the GL Gem Spectrometer which has over 100 users world-wide. The operation of the Raman unit is easy to learn as is the calibration procedure in case the unit has been transported and/or exposed to shock. A large database for gems and minerals is available to match a spectrum. Like a GLGemSpec spectrum file it can be saved and imported into Spekwin 32 for further processing and editing (see spectral graphs on this page).
The package comes with a support CD (including video) for proper operation of the GL Gem Raman; a trained gemmologist should be able to follow and execute the step-by-step instructions including the calibration procedure if necessary. A 2 1/2 hour workshop (GEM 370 offered by the Canadian Institute of Gemmology and other industry groups in the future) is recommended for gemmologists, mineral collectors and other users; we also provide assistance via Skype video-conferencing.
Warning for Students in Gem ID Classes
It may not be widely known that strong fiber-optic light sources can cause damage to the eye; reflections coming off the surface of a gem while being observed with a spectroscope (in particular the small diffraction grating type) can cause burns to the retina which in some cases cannot be repaired.
In earlier newsletters I have also warned against the use of green and/or blue lasers for gem identification or fluorescence testing without proper eye-protection. A much safer option is the GL Gem Spectrometer or the GL Gem Raman where the sample area is fully secured and the spectral graph is seen on the computer monitor.
GEM 250 GEM IDENTIFICATION II (Advanced)
In this course students will learn state-of-the-art techniques including immersionscope, konoscope, advanced spectroscopy, etc. designed to identify confidently any gemstone encountered in the industry. Between 100 and 120 challenging gems including the most recent synthetic and imitation gem materials are available for testing.
Here a brief list of man-made gems in our study collection: Chatham, Kashan, Ramaura, Knischka, Lechleitner, Regency, Biron, Lenix, Gilson, Tairus rubies, sapphires, emeralds, alexandrite, opal and many others. Gem enhancement techniques such as heat-alteration, surface colour diffusion, irradiation and glass filling are studied.
To Register, please call: 604-530-8569
GEM 370 GL Gem Raman Workshop
This course is for current or future users of the GL Gem Raman system.
- Using PowerPoint presentations the development and use of Raman spectrometers is introduced.
- Learning step-by-step testing method with GLGemRaman software and searchable database; procedure of proper calibration with Laser Glasses (190-548nm);
- Practical testing of a number of interesting gem materials by the participants under supervision of the workshop facilitator.
GEM 370-2 Tue, May 22 from 6:30 – 9 p.m. (2 1/2 hours)
Location: Vancouver Airport Hotel TBA, Richmond B.C., Canada
Fee: $ 295 (limited to 5 participants). To register on-line go here.
We reserve the right to cancel courses if there is insufficient enrolment; upon return of all course materials students will receive a full refund for the tuition paid but no other compensation can be offered.
Please wait with travel arrangements until final confirmation.
The Canadian Institute of Gemmology is a member of the World Gem Society.
For a nominal fee you can access a variety of resources available.
Wolf Kuehn, B.A., M.A., Dipl.oec, F.G.A., F.G.G. – Director of Education
© 2012 Canadian Institute of Gemmology, Vancouver, Canada – www.cigem.ca
The name and logo “Canadian Institute of Gemmology” and the designation Accredited Gemmologist (C.I.G.)® are registered trade/certification marks (Registration # TMA407372 CIPO)