We only sell gems we would want to purchase ourselves. When shopping for a colored gemstone on Gemvara, you can assume the gems are enhanced by trade-accepted practices, like heating. Some varieties are almost always enhanced, like Ruby, Emerald, Sapphire, Blue Topaz, Black Onyx, Tanzanite, Black Diamond, and Citrine. (If you prefer an unenhanced gemstone, in particular, a fine ruby, emerald, or sapphire, you should expect to pay a premium and receive a report from a well-respected laboratory like the Gemological Institute of America confirming the gem's natural origin.) Gemvara does not sell gemstones that have been treated in non-standard ways, like bulk diffusion, glass filling, lasering, or coatings.