naumannite

Naumannite is a mineral with the chemical formula Ag2Se. It is a silver selenide and belongs to the chalcogenide group. Naumannite is known for its metallic luster and is typically silver-white to gray in color. It crystallizes in the monoclinic crystal system, though it is often found in massive or granular forms. The mineral is relatively soft, with a Mohs hardness of around 2.5 to 3. Its specific gravity is approximately 7.8.

Naumannite is a rare mineral, often found in hydrothermal veins associated with other silver and selenium minerals. It can also occur in some sedimentary deposits. Notable occurrences include the Harz Mountains in Germany, the Puno region of Peru, and parts of Russia. Due to its rarity and the presence of selenium, naumannite is not a significant source of silver extraction, although it contributes to the overall understanding of silver and selenium geochemistry. It is of interest to mineralogists and geochemists studying the formation of ore deposits.