Amethyst geode pair from Rio Grande do Sul in Brazil (135 cm high)

Amethyst is a purple 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 had 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 Bishop's Stone because it was once a beloved gemstone for ecclesiastical dignitaries, and it was said to possess magical powers. It was the symbol of lovers, the stone of moderation, a protector against sorcery and witchcraft. In Jacob van Maerlant's writings, the explanation can be found that the stone drives away drunkenness. It has been assumed that the Greek name means "against intoxication": one could not get drunk from wine drunk from a cup made of amethyst. Formation: metamorphites, hydrothermal, alluvial deposits. The crystals always grow on a substrate, the prisms are often weakly developed, and therefore the crystal points of spitamethyst dominate; here, the color is also the most intense. These sections are knocked off, that is, broken off for further use. By burning at a temperature between 470 and 750 degrees, light yellow, reddish-brown, green, or colorless varieties are created. There are amethysts that gradually fade in daylight. With radium irradiation, the original color can be restored. The color is caused by iron in combination with ionizing radiation. Under artificial light, amethyst is less beautiful. Occurrence As early as the Middle Ages, Brazil could boast of its amethyst deposits; they are found, among other places, in Bahia, Minas Gerais, and Mato Grosso. Recently, the so-called ametrine is being mined in Bolivia, a combination of amethyst and citrine, 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. In Canada, Mexico, Bolivia, India, Myanmar, Japan, China, and Korea, as well as in Sri Lanka, Zimbabwe, Congo, and Australia, there are also significant producers. In Russia, amethyst is found, among other places, in the Urals, Yakutia, and the Kola Peninsula. Amethysts are also found in Armenia, Germany, the Czech Republic, Slovakia, Bulgaria, Switzerland, and Ireland. Amethyst rarely forms larger pure crystals. In the British Museum, there is 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 possesses a cut amethyst from Brazil weighing 1362 carats and one from North Carolina weighing 202.5 carats. Amethysts are often used in state jewels, such as the scepter of Catherine the Great and the scepter of the British crown.