Trapezium Amethyst (0.7-5 kg) in top color and crystallization from Berjinho das Amethista on a pedestal in top quality (only found once in 2018)

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 αμεθυστος (amethystos). Amethyst was already known to the Egyptians, Etruscans and Romans, and Pliny the Elder described amethyst. In ancient China, small gems were cut from amethyst. Amethyst was also highly prized in Europe during the Middle Ages. Known as the bishop's stone, amethyst once enjoyed popularity among church dignitaries due to its alleged 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 drives away drunkenness. It has been assumed that the Greek name would mean "against intoxication": one would not get drunk from wine drunk from a cup made of amethyst. Origin: metamorphic, hydrothermal, alluvial The crystals always grow on a substrate; the prisms are often poorly developed, and as a result, the crystal points of spit amethyst predominate. Here, the colour is also the most powerful. These parts are knocked off, that is, broken off for further use. Firing at a temperature between 470 and 750 degrees creates light yellow, reddish brown, green, or colourless varieties. There are amethysts that gradually fade in daylight. Radium irradiation can restore the original colour. Ionising radiation, in combination with iron, causes the colour. Amethyst is less attractive in artificial light. Occurrence Brazil has been mining amethyst deposits since the Middle Ages, primarily in Bahia, Minas Gerais, and Mato Grosso. Recently, the so-called ametrine, an amethyst-citrine, has been mined in Bolivia, in which the violet and yellow colours alternate, but the transition between the colours 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, Korea, Sri Lanka, Zimbabwe, Congo and Australia are also important producers. Russia finds amethyst in the Urals, Yakutsk, and on the Kola Peninsula. The amethyst is also found in Armenia, Germany, the Czech Republic, Slovakia, Bulgaria, Switzerland, and Ireland. Amethyst rarely forms larger, pure crystals. The British Museum has 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 has a cut amethyst from Brazil of 1362 carats and one from North Carolina of 202.5 carats. Amethysts are often used in state jewels, like Catherine the Great's and the British crown's sceptres.