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www.mineralgallery.co.za Minerals K-O |
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Magnetite |
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Name
Magnetite
Chemistry
Fe2+Fe3+2O4
Uses
Major ore of iron and as mineral specimens
Color
Grayish black, Iron black.
Hardness
5½ - 6½
Specific gravity
5.1+
Crystals
Octahedrons or dodecahedrons
Accompanied by:
Apatite, Calcite, Chlorite (schists), Garnet, Hematite, Ilmenite, Phlogopite, Pyrite, Talc
Fracture
Subconchoidal to uneven
Luster
Metallic
Cleavage
None
Streak
Black
Similar to:
Chromite, Franklinite, Ilmenite, Spinel
Magnetite derives its name from its natural magnetism and also after the ancient region in Greece that was well-known for its metal production.
Magnetite is a black oxide in the spinel group.
Magnetite is also common iron oxide mineral, with a very high iron content. It occurs in many igneous rocks.
Coloration varies from pale brown to iron black.
Hematite commonly forms Pseudomorphs over Magnetite. These Pseudomorphs are known as Martite, and their appearance may be similar to regular Magnetite.
Known in the gemstone trade as Lodestone.
Magnetite forms a brown-yellow rust coating if washed or kept in a damp area. If washed, it should be dried immediately. To prevent rusting, specimens should be stored in dry areas.
