Amethyst

Amethyst is a purple variety of Quartz that owes its violet color to irradiation, impurities of iron and in some cases other transition metals. The name comes from the Koine Greek αμέθυστος amethystos from α- a-, "not" and μεθύσκω (Ancient Greek) methysko / μεθώ metho (Modern Greek), "intoxicate", a reference to the belief that the Amethyst crystal protected its owner from drunkenness. Ancient Greeks wore amethyst and carved drinking vessels from it in the belief that it would prevent intoxication.

Amethyst is associated with the crown chakra.