In nature, copper mainly exists in the form of copper sulfide, mainly chalcopyrite, chalcopyrite and bornite. The main component of chalcocite is cuprous sulfide, which is lead gray; The main component of bornite is copper and iron sulfide, which is dark copper red. It often coexists with chalcopyrite and chalcocite, and its actual composition changes greatly. The main component of chalcopyrite is copper disulfide, which is brass yellow. It usually coexists with pyrite, galena, sphalerite, bornite, chalcocite, calcite and timely.