Amethyst is a violet variety of quartz often used in jewelry.
The name comes from the Koine Greek ἀμέθυστος amethystos a reference to the belief that the stone protected its owner from drunkenness. The ancient Greeks wore amethyst and carved drinking vessels from it in the belief that it would prevent intoxication.
It is one of several forms of quartz. Amethyst is a semiprecious stone and is the traditional birthstone for February.