Regarding treated-color natural topaz, reddish brown is produced by ionizing irradiation, and blue is produced by high-energy electron irradiation with subsequent heat treatment, not dying. Mystic topaz is produced by a chemical vapour deposition (CVD) coating on natural topaz, not dying. There is no way to dye a topaz unless it is badly fractured, and it would be very easy to detect with the naked eye. In the early 2000’s, research scientists succeeded in synthesising light gray to colorless topaz crystals as overgrowths on natural topaz by hydrothermal crystal formation (Renfro, N. et al. G&G LXVI 2010 pg. 271). However, there is zero commercial demand for such a product, therefore, my statement “there are no synthetic topaz made anywhere in the world” is correct. No one is producing lab grown topaz. All claimed “Lab grown” or “synthetic” topaz on the market (eBay, Etsy, Alibaba etc.) are imitations, not topaz.
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