Amethyst is the popular purple variety of Quartz. It is the birthstone for February is the gem for 6th anniversaries. Amethyst has a hardness of 7 on Mohs scale. Amethyst is pale to deep purple and available in calibrated sizes as well as large individual gems and interesting fancy cuts. Amethyst is mined in Zambia, Madagascar, Namibia, Tanzania, Brazil and Uruguay. It is doubly refractive with an RI of 1.530 – 1.550 and Amethyst has a specific gravity of 2.65 – 2.66.