chalcogenite

Chalcogenite is a rare mineral composed of copper, iron, and sulfur. Its chemical formula is CuFeS2. It is a member of the chalcopyrite group and is polymorphous with cubanite. Chalcogenite is typically found in hydrothermal veins and in igneous rocks, often associated with other copper and iron sulfides. It has a metallic luster and a brass-yellow color, though it can sometimes appear tarnished or iridescent. Its hardness is relatively low, ranging from 3 to 4 on the Mohs scale. The mineral is brittle and has a conchoidal fracture. Chalcogenite was first described in 1845 and named after the Greek word "chalcogen," meaning "copper-former," due to its association with copper deposits. While not a major ore of copper, it can be a minor source. It is primarily of interest to mineral collectors and geologists studying ore formation. Its occurrence is relatively widespread, with notable deposits found in various locations worldwide, including the United States, Canada, Chile, and Australia.