For more than a year, U.S. gem labs have been telling Thai gem treaters that they’ve found beryllium diffusion in corundum treated in Thailand.
Because of the ethical and monetary consequences associated with nondisclosure of treatments, the U.S. gemological community has insisted that the Thais disclose all enhancements. The gem treaters have replied that they use only heat, and they’ve insisted there’s no diffusion into sapphire. Now their position has changed.
In a press release translated by Thaigem.com, the gem treaters in Chanthaburi, Thailand, have admitted using chrysoberyl—which, when heated to high enough temperatures, releases beryllium—as a coloring agent. According to the release, “At an emergency meeting of the Chanthaburi Gem & Jewelry Association (CGA) on Feb. 20, 2003, some of the biggest names in corundum heating have formally agreed to disclose the use of beryllium to enhance color. The 60 association members present unanimously agreed that: Chrysoberyl is being intentionally added to the crucible during the new heat treatment to enhance color in corundum. All association members are obligated to disclose and to differentiate the new treatment when selling to customers.”
The release also notes that heaters and dealers who don’t respect the new regulations won’t receive CGA approval. It advises bringing disclosure disputes to the immediate attention of CGA’s disclosure committee, which “will both liaise between buyers and sellers to resolve disputes, and take appropriate action toward respective members.”
According to the International Colored Gemstones Association (ICA), corundum products treated by diffusion must be defined as “treated” and be disclosed using the letter “T” under ICA’s N.E.T. disclosure code.
CGA members will not use “T” because, they say, the word “treatment” has a negative connotation. Instead, they will disclose using the following codes: N = natural unheated corundum; E = thermal enhancement; A = thermal enhancement of corundum together with other minerals in an environment that allows the introduction of beryllium and other elements into corundum; T = treatments.
Don Kogen, president of Thaigem.com and ambassador to the CGA, stated, “As exemplified by the new disclosure system, the CGA’s renewed commitment to professionalism will ensure consumer confidence and firmly position Chanthaburi as a reliable and credible source for ruby and sapphire.”
But can you identify it? Identifying diffusion-treated padparadscha-color material is easy—standard gemological testing reveals a shallow layer of added color, and the sudden increase of rare “padparadschas” in the market aroused enough suspicion to warrant testing. However, it’s possible to treat sapphire of every color in this manner, but with the color diffused throughout the stone, not added in an easily identified layer. Gem merchants are worried that they could unwittingly buy a beryllium-diffused sapphire that appears to be a fine-color, traditionally heated sapphire.
“It’s a major problem,” says Roland Naftule, former AGTA board member and colored-stone wholesaler with Nafco in Scottsdale, Ariz. “The treatment can be done anywhere, and these stones can be sprinkled in parcels.” He notes that beryllium-treated sapphire has been in the market for two years in yellows and oranges, and within recent months colors that appear as “fine Ceylon blues” have entered the market. He says poor-color Umba River [Tanzanian] sapphires are being treated to create salable “yellows, oranges, and reds [ruby].”
Laboratories are using a number of identification indicators and tools to make their determinations. These include color distribution, unusual colors, altered inclusions, electrical resistance, fluorescence, infrared spectra, and photoluminescence. The more expensive and reliable tests include laser ablation and SIMS, which provide a quantitative chemical analysis.
But laboratories can’t identify all of the beryllium-diffusion-treated sapphires, and there’s fear that sapphire will follow the route of blue topaz, which is assumed to be treated unless proven natural. Naftule already makes that case, stating that “all colors of sapphire are—or can be assumed to be—beryllium treated.”
At the final corundum conference in Tucson, Laura Barringer, a senior buyer for West Coast retailing giant Ben Bridge Jewelers, said the company must err on the conservative side when reordering sapphire and ruby from suppliers. She said Ben Bridge would purchase material if a supplier agreed not to buy any beryllium-treated material but added that the company would continue to spot-check for treatment. “I look to my supplier,” says Barringer, “and they need to go to their supplier.”
Dallas appraiser Patti Geolat noted that she was going to have to rewrite her limiting conditions because she’s unable to identify this material. Geolat says she will suggest that her clients get a laboratory report.
“We’re all worried,” says Oscar Heyman’s Jeffrey Bilgore, a former AGTA director and laboratory committee chairman. “It’s the basic right of the buyer to know what it is they are buying—to expect and require honesty and disclosure. It’s all about confidence in the marketplace.”