- a very common black iron oxide mineral, Fe3O4, that is strongly attracted by magnets: an important iron ore.
- a black magnetic mineral, found in igneous and metamorphic rocks and as a separate deposit. It is a source of iron. Composition: iron oxide. Formula: Fe 3 O 4 . Crystal structure: cubic
n.magnetic iron ore, 1840, from German magnetit; see magnet + -ite (2).
- 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.