There has been enough postings on this subject to pique my curiosity.
First I went to www.gia.edu and did a search on synthetic amethyst.
Found lots of interesting reading, but nothing about them and
I then did a Google search using the following search term thaigems
synthetic amethyst GIA
and other than loads of marketers who load their webpage with search
terms to draw people to their sites nothing of interest was returned.
I then did a search on thaigem and GIA and found some references to a
dispute concerning heat treatment of sapphires. I then narrowed the
search to the following search term:
thaigem gia heat treat surface sapphires
and found a few interesting articles about a dispute between the GIA
and Thai heat treaters in general dating back to 2002. Thaigems was
mentioned in several articles.
The dispute centered on if sapphires that had been treated should be
labeled has heat treated (has was being done) or surface diffusion
You will find some interesting reading and insight into the
controversies surrounding this issue and classification of treatments
and / or enhancements in general.
Some interesting links are
I'm sure if thaigems had been caught out and it was public enough to
cause a precipitous drop in sales that there would have been some
mention of it that I could have found. I half suspect the 200
synthetic Amethyst is a distortion of the above controversy.
Just my 2 cents