Description
Amethyst is a violet variety of the mineral quartz (SiO2) and is the most sought-after stone of the quartz group. Etymology: The name amethyst comes from the Greek word αμεθυστoς (amethystos). Amethyst was already known to the Egyptians, Etruscans, and Romans, and was described by Pliny the Elder. In ancient China, small gems were cut from amethyst. In the Middle Ages, amethyst was also highly prized in Europe. It was called the bishop's stone because it was once a favored gemstone for ecclesiastical dignitaries and was believed to possess magical powers. It was the symbol of lovers, the stone of temperance, and a protector against sorcery and witchcraft. Jacob van Maerlant explains that the stone dispels drunkenness. It has been assumed that the Greek name means "against intoxication": one would not get drunk from wine drunk from an amethyst cup. Origin: metamorphic, hydrothermal, and alluvial. The crystals always grow on a substrate; the prisms are often weakly developed, and therefore the crystal points of amethyst predominate. Here, the color is also most intense. These parts are knocked off, that is, broken off for further use. Firing at a temperature between 470 and 750 degrees Celsius produces light yellow, reddish-brown, green, or colorless varieties. Some amethysts gradually fade in daylight. Radium irradiation can restore the original color. The color is caused by iron in combination with ionizing radiation. Amethyst is less attractive in artificial light. Occurrence: As early as the Middle Ages, Brazil boasted its amethyst deposits; they are mined in places such as Bahia, Minas Gerais, and Mato Grosso. Recently, the so-called ametrine, an amethyst-citrine, has been mined in Bolivia, where the violet and yellow colors alternate, but the transition between the colors is sharply defined. Amethysts are also known in the United States, namely in Montana, Maine, Georgia, and Arizona. Canada, Mexico, Bolivia, India, Myanmar, Japan, China, and Korea are also important producers, as are Sri Lanka, Zimbabwe, Congo, and Australia. In Russia, amethyst is found in the Urals, Yakutsk, and the Kola Peninsula, among other places. Amethysts are also found in Armenia, Germany, the Czech Republic, Slovakia, Bulgaria, Switzerland, and Ireland. Larger, pure amethyst crystals are rare. The British Museum holds a unique cut stone weighing 343 carats. Other, smaller stones weigh less; they usually come from Brazil. The Smithsonian Institution in Washington, DC, even possesses a cut amethyst from Brazil weighing 1,362 carats and one from North Carolina weighing 202.5 carats. Amethysts are often used in state jewels, such as Catherine the Great's scepter and the British Crown Scepter.
