Copper ores are usually a combination of copper sulfides or oxides and other minerals. When reacting with sulfuric acid, they form blue-green copper sulfate. Natural copper minerals come in various colors. Chalcopyrite is bright yellow, cuprite is dark copper red, and after oxidation, it turns into blue-purple patches; sphalerite (sulfide of copper) is lead gray; cupriferous blue (sulfide of copper) is indigo blue; malachite is steel gray; azurite (formerly known as zengqing or shikeng) is bright blue.

Magnetite is an oxide mineral, with the main component being iron(III) oxide (Fe₃O₄). It belongs to the isometric crystal system. The common crystal forms are octahedra or rhombohedral dodecahedra, and the aggregates are mostly in the form of granular or block-like. Its color is iron black, and the streak is black. It has a semi-metallic luster and strong magnetism. As the main mineral raw material for iron smelting, magnetite is used in industry for steel production and can also be ground into fine particles for use as a medium in mineral separation.

Hematite is an oxide mineral with the chemical composition Fe₂O₃, belonging to the hexagonal crystal system, and is one of the main ore minerals of iron.Hematite is widely distributed and commonly found in various rocks; it mainly forms through hydrothermal processes, sedimentation, or metamorphism.As one of the important raw materials for iron smelting, hematite has a high iron content of up to 70% and can be produced in large quantities.