Silvanite
Silvanite is a rare mineral with the chemical formula Ag3AuTe2, making it a telluride of silver and gold. It is typically found in epithermal gold and silver deposits. The mineral is known for its metallic luster and can range in color from pale brass-yellow to silvery-white. Its hardness is relatively low, typically around 2.5 to 3 on the Mohs scale. Silvanite is often associated with other telluride minerals such as calaverite, petzite, and altaite, as well as common ore minerals like pyrite and chalcopyrite. Geologically, silvanite is believed to have formed from hydrothermal solutions at moderate temperatures. While not a primary source of gold or silver due to its rarity, it can be a minor component in some precious metal ores. It was first described in 1845 from a discovery in the Zlatoust district of the Ural Mountains in Russia. Notable occurrences include areas in Romania, Australia, Canada, and the United States. Its presence can sometimes indicate the potential for richer gold and silver mineralization in a given area, making it of interest to mineral prospectors.