The Probert Encyclopaedia of Rocks & Minerals

MAGNETITE

Magnetite is an oxide of iron occurring in isometric crystals, also massive, of a black colour and metallic lustre. It is readily attracted by a magnet and sometimes possesses polarity, being then called loadstone. It is an important iron ore and is also called magnetic iron. Magnetite has the formulae Fe3O4 and a relative hardness of 7.
Research Magnetite