The mineral form of black iron oxide, Fe3 O4 , that often occurs with magnesium, zinc, and manganese and is an important ore of iron.
A black, hard, magnetic mineral, (Fe,Mg)Fe2O4, that is a major ore of iron.
A brown to black mineral that is strongly magnetic. It crystallizes in the cubic system and commonly occurs as small octahedrons. Magnetite occurs in many different types of rock and is an important source of iron. Chemical formula: Fe3O4.