Magnetite - Wikipedia
Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe 3 O 4.It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. It is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of ...