An iron oxide mineral (Fe3O4) with a very strong natural magnetism. It is a valuable ore of iron.
| Magnetite | |
|---|---|
|
Magnetite from the Kola Peninsula, Russia |
|
| General | |
| Category | Mineral |
| Chemical name | iron(II,III) oxide |
| Chemical formula | Fe3O4 |
| Identification | |
| Colour | Black, greyish |
| Crystal habit | Octahedral, fine granular to massive, |
| Crystal system | Isometric |
| Cleavage | Indistinct |
| Fracture | Uneven |
| Mohs Scale hardness | 5.5 - 6.5 |
| Luster | Metallic |
| Refractive index | Opaque |
| Pleochroism | None |
| Streak | Black |
| Specific gravity | 5.17 - 5.18 |
| Fusibility | ? |
| Solubility | ? |
| Major varieties | |
| Lodestone | Magnetic with definite north and south poles |
Magnetite is a ferrimagnetic mineral with IUPAC name iron(II,III) oxide and with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The relationships between magnetite and other iron-rich oxide minerals such ilmenite, hematite, and ulvospinel have been much studied, as the complicated reactions between these minerals and oxygen influence how and when magnetite preserves records of the Earth's magnetic field.
Small grains of magnetite occur in almost all igneous rocks and metamorphic rocks.
Distribution of deposits
Magnetite is sometimes found in large quantities in beach sand.
Large deposits of magnetite also are found in Kiruna, Sweden, the Pilbara region in Western Australia, and in the Adirondack region of New York in the United States. 17:169-95 PDF file Bio-magnetics Magnetic bacteria (Italian)
User Comments Add a comment…