Prairie Tanzanite, flat stone from Wyoming, USA

Tanzanite is a zoisite variety and is named after Tanzania. Although the inhabitants of Tanzania knew the stones for a long time, tanzanite was discovered only in 1967 for precious stone science by an Indian prospector Manuel de Souza. However, this thought initially found a deposition of sapphire. Tanzanite was then described by the German geological association as a variety of zoisites. The stone was especially famous as a jewel of film star Elizabeth Taylor. Today tanzanite belongs to the most popular gems. Tanzanites are found in the area of ​​the Merelani Hills (also known as Meralani, Merarani or Mererani Hills), near Arusha and Moshi in Tanzania. They form prismatic crystals with marked vertical slots and occur in pegmatic-hydrothermal veins. The Smithsonian Institute in Washington's collection contains beautiful rough and tanned tanzanites. The literature describes a carved stone of 122.7 carats and a tanzanite cat eye of more than 200 carats. Tanzanites are used in all ornamental forms. Sometimes the color can be improved by heating to 400-500 degrees centigrade.