Amethyst

Amethyst is a violet variety of quartz. The name comes from the Koine Greek ἀμέθυστος amethystos from α- a-, 'not' and μεθύσκω methysko / μεθύω methyo, 'intoxicate', 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.

Formation & Geology

Amethyst is produced in abundance from the state of Minas Gerais in Brazil where it occurs in large geodes within volcanic rocks. Many of the hollow agates produced in Brazil and Uruguay contain a crop of amethyst crystals in the interior. It is also found in South Korea, Russia, Austrian Alps, and the United States.

Physical Characteristics

Amethyst is a purple variety of quartz (SiO2) and owes its violet color to irradiation, impurities of iron and in some cases other transition metals, and the presence of trace elements, which result in complex crystal lattice substitutions. The hardness of the mineral is the same as quartz, thus it is suitable for use in jewelry.

Historical Significance

Amethyst was a precious stone used by the ancient Egyptians and was largely employed for intaglio engraved gems in antiquity. Medieval European soldiers wore amethyst amulets as protection in battle in the belief that amethysts heal people and keep them cool-headed.

Fading & Heat Treatment

Amethyst is generally stable, but prolonged exposure to intense sunlight can cause its violet color to fade over time. It is best to store amethyst jewelry in a dark box when not in use. Additionally, most "Citrine" on the market is actually amethyst that has been heat-treated. When heated to high temperatures, the purple iron impurities turn yellow or orange.