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Not to be confused with Magnesite or Maghemite.
Magnetite
Magnetite from the Kola Peninsula, Russia |
General
Category
| Mineral |
Chemical formula
| iron(II,III) oxide, Fe3O4 |
Identification
Color
| Black, grayish |
Crystal habit
| Octahedral, fine granular to massive |
Crystal system
| Isometric |
Cleavage
| Indistinct |
Fracture
| Uneven |
Mohs scale hardness
| 5.5–6.5 |
Luster
| Metallic |
Streak
| Black |
Specific gravity
| 5.17–5.18 |
Refractive index
| Opaque |
Major varieties
Lodestone
| Magnetic with definite north and south poles |
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. The Curie temperature of magnetite is 858 K. |
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