If You Can’t Stand the Heat, Get Out of the Gem Business, Part II

In the spring of 1979, the Gemological Institute of America's Gem Trade Labs (GTL) began to see a large number of heat-treated sapphires from Sri Lanka. Robert Crowningshield, then director of GTL in New York, called heat-treating sapphires "one of the best kept commercial secrets in the jewelry industry." That's because the Sri Lankans (and later the Thais) had been treating stones for almost six decades, but neither GIA nor the rest of the industry learned of it until the 1970s. In "The History and Politics of Heat," published last year in Gem Market News by Gemworld Inter-national, Northbrook, Ill., gemologist and corundum expert Richard Hughes of Pala International, Fallbrook, Calif., revealed that GIA had seen the heated stones but didn't realize it. Hughes and others have found the particulars in GIA's own Gems & Gemology magazine. "In 1966, Robert Crowningshield of the GIA
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