June 25, 1999
GIA Discusses Findings on GE Process
During a special session at the International Gemological Symposium in San Diego, CA, this week, GIA reported it found "recognizable features" that may help identify General Electric's process used to change color in diamonds.
Top GIA officials and scientists discussed preliminary results from their studies of more than 200 diamonds, submitted by GE and the diamonds' distributor, Lazare Kaplan International. The studied diamonds had all undergone the secretive process, which GE and LKI said was unidentifiable and, therefore, didn't need to be disclosed as a treatment.
However, researchers were able to discover identification features in the GE-processed diamonds, though they said it was too early to reveal what they were. Researchers at the session lamented not having the chance to study the diamonds before they underwent the process. The studied diamonds were between 0.3 and 7 carats, but mostly in the 1-3-ct. range, primarily fancy shapes, D-H in color, IF-I2 in clarity with a concentration in the IF-SI1 range, mostly Type II with some Type I and distinguished by "unusual gemological features."
GIA continues to refer to the diamonds as "processed" instead of "treated" or "enhanced" because it still hasn't confirmed what happens to them, said President William Boyajian. When it does uncover the nature of the process, how much information it can release to the industry will be another issue. "For GIA it is a delicate balance: to protect GE's proprietary know-how and to be able to report findings without disclosing the know-how," Boyajian said.
GIA has conducted its own color experiments for years to understand possibilities and identification clues, said Jim Shigley, director of research. As part of those experiments, GIA successfully added and removed color in Type I and II diamonds. "What we've found in our own experiments should be called a treatment," said Boyajian.
Boyajian said GE and LKI agreed not to sell processed rough diamonds and will cooperate to laser-inscribe processed diamonds for identification. However, GIA's Gem Trade Lab last week received two processed diamonds on which the laser inscriptions had been partially polished off. The possibility that the inscriptions could be erased making detection difficult or impossible is a fear among industry members worried about disclosing the treatment.
GIA's study was an extensive effort that pulled researchers from other duties to focus on the issue, said Boyajian.
- by Robert Weldon, G.G.