Chalcocite is a mineral composed primarily of copper(I) sulfide, with the chemical formula Cu2S. It is an important ore of copper and is typically found in hydrothermal veins and as a secondary mineral in copper deposits. Chalcocite has a metallic luster and can appear in various colors, including dark gray to black. This mineral is often associated with other copper minerals, such as chalcopyrite and bornite. Chalcocite is significant in mining because it can be processed to extract copper, which is essential for various industrial applications, including electrical wiring and plumbing.