amethist

Amethist is an alternative spelling found in some historical texts or in certain languages for amethyst, the violet variety of quartz. In contemporary mineralogy, the standard term is amethyst, and amethist is not recognized as a separate mineral species. When used, it refers to the same mineral.

Amethyst is a silicate mineral with the chemical formula SiO2. It is a member of the quartz family and is valued for its violet to purple color, which results from trace amounts of iron and exposure to natural radiation. The crystal system is hexagonal; crystals often form prismatic hexagonal sections and can occur as single crystals or within geodes and vugs. The Mohs hardness is 7, making it suitable for most jewelry; transparency ranges from transparent to translucent, with color zoning and pleochroism possible in some specimens.

Occurrence and sources: Amethyst is found worldwide. Major sources include Brazil and Uruguay, but notable deposits also occur in Zambia, Madagascar, Russia, and North America. It forms in geologic environments such as volcanic rocks and hydrothermal veins, and is commonly associated with other quartz varieties, calcite, and other minerals.

Uses and value: Amethyst has long been used in jewelry and carvings. While generally less expensive than diamonds or sapphires, high-quality amethyst crystals can command significant value, especially for large, deep-colored stones.

Treatments and synthesis: Natural amethyst can be heat treated to produce citrine. Artificial or laboratory-grown amethyst crystals are produced by hydrothermal methods and are chemically identical to natural specimens.

Etymology: The name amethyst derives from Greek amethystos, meaning not intoxicated, reflecting the ancient belief that the stone protected its wearer from drunkenness.