Magnetite

n. black iron oxide mineral that is an important ore of iron

Magnetite is not to be confused with Magnesite or Magnemite. Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron(II,III) oxide and the common chemical name ferrous-ferric oxide. The formula for magnetite may also be written as FeO.Fe2O3, which is one part wüstite (FeO) and one part hematite (Fe2O3). This refers to the different oxidation states of the iron in one structure, not a solid solution.
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Noun
1. an oxide of iron that is strongly attracted by magnets
(synonym) magnetic iron-ore
(hypernym) iron ore
(substance-holonym) lodestone, loadstone

n. magnetite, loadstone, stone that has magnetic properties

n. magnetite, black iron oxide mineral that is an important ore of iron