Amethyst belongs to the macrocrystalline branch of the quartz group of minerals. The amethyst’s colour varries from purple and violet to pale red-violet. Its colour comes from the iron and aluminium impurities. Furthermore, this fine gemstone is found mainly in Brazil but also “in Bolivia, Canada, India, Madagascar, Mexico, Myanmar (Burma), Namibia, Russia, Sri Lanka, United States (Arizona), Uruguay and in Zambia”. Besides, Amethyst is a symbol of sobriety : in Ancient Greece, the name amethyst meant “not drunk”.