Copper sulfide is a chemical compound made up of copper and sulfur, with the formula CuS. It typically appears as a dark, black solid and is found in nature as a mineral, often in association with other minerals like chalcopyrite and bornite. This compound is important in the mining industry, as it is a primary source of copper. When heated, copper sulfide can be converted into copper metal through a process called smelting, which is essential for producing electrical wiring and various other applications in technology and construction.