Amethyst with sawn-off base in A-Quality.

Amethyst is a violet variety of the mineral quartz (SiO2) and is the most sought-after stone from the quartz group. Etymology: The name comes from the Greek αμεθυστoς (amethystos). Amethyst was already known to the Egyptians, Etruscans and Romans, and Pliny the Elder already described amethyst. In ancient China, small gems were cut from amethyst. In the Middle Ages, amethyst was also highly valued in Europe. It was called a bishop's stone because it used to be a popular gemstone for church dignitaries and was said to possess magical powers. It was the symbol of those in love, the stone of temperance, 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 cannot get drunk from wine drunk from a cup made of amethyst. Origin: Metamorphites, hydrothermal, alluvial deposits. The crystals always grow on a sublayer, the prisms are often weakly developed and therefore the crystal points dominate spitamethyst; here the color is also the most powerful. These parts are knocked off, that is, broken off for further use. Burning at a temperature between 470 and 750 degrees produces light yellow, reddish brown, green or colorless varieties. There are amethysts that gradually fade in daylight. The original color can be restored with radium irradiation. The color is caused by iron in combination with ionizing radiation. Amethyst is less attractive in artificial light. Occurrence Already in the Middle Ages, Brazil could boast of its amethyst deposits, which are mined in Bahia, Minas Gerais and Mato Grosso, among others. 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, and Sri Lanka, Zimbabwe, Congo and Australia are also important producers. In Russia, amethyst is found in the Urals, Yakutsk and on the Kola Peninsula. Amethysts are also found in Armenia, Germany, Czech Republic, Slovakia, Bulgaria, Switzerland and Ireland. Amethyst only rarely forms larger pure crystals. The British Museum contains a unique cut stone of 343 carats. Other, smaller stones weigh less; they usually come from Brazil. The Smithsonian Institution in Washington, D.C. even owns a cut amethyst from Brazil of 1,362 carats and one from North Carolina of 202.5 carats. Amethysts were often used in state jewelry, such as the scepter of Catherine the Great and the scepter of the British Crown.