Amethyst is a violet variety of quartz. The name comes from the Greek word “amethystos “ meaning "not intoxicated" in translation, a reference to the belief that the stone protected its owner from drunkenness.
Amethyst occurs in primary hues from a light pinkish violet color to a deep purple color. Amethyst may exhibit one or both secondary hues, red and blue. The ideal grade is called "Deep Siberian" and has a primary purple hue of around 75–80%, with 15–20% blue and (depending on the light source) red secondary hues. ‘Rose de France’ is defined by its markedly light shade of the purple, reminiscent of a lavender/lilac shade. These pale colors were once considered undesirable but have recently become popular due to intensive marketing.
The biggest factor in the value of amethyst is the color displayed. The highest-grade amethyst (called "Deep Russian") is exceptionally rare and therefore when one is found, its value is dependent on the demand of collectors. Now and then Nature gives us a surprise by having created bicolored stones, like the ones recently found in Bolivia in the form of caustics crystal nuggets. This variety is known as ametrine, for in its formation certain energy states of iron introduce violet areas to the yellow citrine.
Green quartz is sometimes incorrectly called green amethyst, which is a misnomer and not an appropriate name for the gem, the proper terminology being prasiolite. Other names for green quartz are vermarine or lime citrine.
The deposits with the greatest economic significance are in various states in southern Brazil and in neighboring Uruguay. The third major export country is Madagascar. However, this gemstone is spread all over the world. High-quality amethyst can be found in Siberia, Sri Lanka, and the far East. It is also found and mined in South Korea. The largest opencast amethyst vein in the world is in Maissau, Lower Austria. Much fine amethyst comes from Russia, especially from near Mursinka in the Ekaterinburg district, where it occurs in drusy cavities in granitic rocks. Many localities in south India yield amethyst while one of the largest global amethyst producers is Zambia. Amethyst occurs at many localities in the United States and is relatively common in the Canadian provinces of Ontario and Nova Scotia.
Amethyst was used as a gemstone by the ancient Egyptians and was largely employed in antiquity for intaglio engraved gems.
According to the ancient Greek saga, Diana turned a nymph whom Bacchus loved into an amethyst; hence the term Bacchus stone. The Greeks believed amethyst gems could prevent intoxication, while medieval European soldiers wore amethyst amulets as protection in battle in the belief that amethysts heal people and keep them cool-headed. Moses described it as a symbol of the Spirit of God in the official robes of the High Priest of the Jews, and the Russian Empress Catherine the Great sent thousands of miners into the Urals to look for it.