Magnetite
Magnetite · Mineral Specimen and Ore Mineral
Crystal System
Cubic (Isometric); habit typically octahedral, dodecahedral, or massive granular
Mineral Group
Oxides; spinel group
Chemical Formula
Fe2+Fe3+2O4
Formation Process
Igneous (accessory mineral in magmatic rocks), metamorphic (regional and contact), and hydrothermal processes. Forms across a wide range of temperatures and pressures.
About This Crystal
Small, dark, metallic-appearing mineral fragment resting on a textured surface. The specimen exhibits a sub-metallic to metallic luster with a black to dark gray color and irregular, broken surfaces showing high reflectivity on certain facets.
Physical Characteristics
Color: Iron-black to brownish-black. Streak: Black. Cleavage: None, but may show parting. Fracture: Uneven to sub-conchoidal. Specific Gravity: 5.17 to 5.18. Tenacity: Brittle. Strongly magnetic.
Optical Properties
Opaque with a metallic to sub-metallic luster. Refractive index is not applicable due to opacity.
Hardness & Durability
Origin Region
Found globally; notable sources include Sweden, Norway, USA (Adirondacks), Russia, and South Africa. Typically forms in igneous and metamorphic rocks.
Hardness & Durability
Mohs hardness of 5.5 to 6.5. Moderate durability, though high magnetism makes it unique. Brittle, but sturdy enough for general handling.
Care & Maintenance
Clean with a soft brush and warm soapy water. Dry thoroughly to prevent oxidation or rusting if trace impurities are present. Store away from moisture.
Rarity & Value
Common mineral, widespread globally. Value is typically low unless in exceptional crystal specimens or as high-grade iron ore.
Special Characteristics
Strong natural magnetism (lodestone variety demonstrates this most strongly), strongly attracted to permanent magnets, and can be magnetized itself.
Lore & History
Historically known as lodestone, it was used by ancient mariners as an early form of compass. In metaphysical practices, it is associated with grounding, alignment of energies, and attraction (manifestation), though these are traditional beliefs.