Amethyst of synthetic quartz is used. Treated amethyst is produced by gamma ray, X-ray or electron beam irradiation of clear quartz (rock crystal) which has been first doped with ferric impurities. On exposure to heat, the irradiation effects can be partially cancelled and amethyst generally becomes yellow or even green, and much of the citrine, cairngorm, or yellow quartz of jewelry is said to be merely "burnt amethyst". The Greek word "amethystos" may be translated as "not drunken", from Greek "a-", "not" + "methustos", "intoxicated". Amethyst was considered to be a strong antidote against drunkenness, which is why wine goblets were
Amethyst its variations are not found in classical sources. However, the titan Rhea does present Dionysus with an amethyst stone to preserve the wine-drinker's sanity in historical text. Tibetans consider amethyst sacred to the Buddha and make prayer beads from it. Amethyst is considered the birthstone of February. In the Middle Ages, it was considered a symbol of royalty and used to decorate English regalia. In the Old World, amethyst was considered one of the Cardinal gems, in that it was one of the five gemstones considered precious above all others, until large deposits were found in Brazil. Amethyst is produced