AGTA and ICA Label Sapphire Treatment

The American Gem Trade Association (AGTA) and the International Colored Gemtone Association (ICA) have joined forces to declare that the sapphire treatment — which turns colorless sapphire to the desired padparadscha color — originating in Thailand should be called a "bulk diffusion process."

According to a joint statement released by the AGTA and ICA, "Given the continued use of this process and the resulting confusion as to its disclosure our associations have found it is necessary to provide absolute clarity regarding its description."

The AGTA's description of the process in its Gemstone Information Manual will be "Bulk Diffusion Process" with an industry-endorsed disclosure code of "U", which is required of AGTA members. If the color of the bulk diffused gemstone does not permeate the entire stone, then the following statement must also appear, printed in a visible location:
"Although the color induced in bulk diffusion treated gemstones is permanent under normal conditions, if it does not permeate the entire gemstone recutting or repolishing is not recommended."

The ICA's code for disclosure, which is required of ICA members, will be "Treated Stone" with the code "T." The "T" category includes all gemstones that require explicit process disclosure. An example of this disclosure would be: The color in this sapphire has been achieved through a process which includes the addition of foreign elements to achieve the desired color alteration. This treatment is a diffusion process and the coloration may be confined only to the surface or in some cases throughout the gemstone. Recutting may result in a change of color.

Posted: August 15, 2002

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