Magnetite
Magnetite · Mineral Specimen and Industrial Ore
Crystal System
Cubic (Isometric); octahedra and dodecahedra, often massive or granular
Mineral Group
Oxides; Spinel supergroup
Chemical Formula
Fe2+Fe3+2O4
Formation Process
Igneous, metamorphic, and sedimentary processes; common in magmatic segregation deposits, high-temperature hydrothermal veins, and metamorphosed iron formations
About This Crystal
Opaque, metallic black to dark grey mineral exhibiting a strong submetallic to metallic luster. It occurs embedded in a weathered, brownish-yellow matrix rich in iron oxides, showing characteristic octahedral crystal fragments.
Physical Characteristics
Color is iron-black to dark grey; streak is black; cleavage is none, parting on {111}; fracture is uneven to subconchoidal; specific gravity is around 5.15-5.18; strongly magnetic; brittle tenacity
Optical Properties
Isotropic in reflected light; highly opaque with a strong metallic luster; no pleochroism or birefringence
Hardness & Durability
Origin Region
Found worldwide; notable deposits in Sweden, Norway, USA (Adirondacks), Russia, and South Africa
Hardness & Durability
Mohs hardness of 5.5 to 6.5; brittle toughness; stable under normal conditions but reactive with strong acids
Care & Maintenance
Clean with mild soap and water; dry thoroughly to prevent rust of associated matrix minerals; store away from moisture
Rarity & Value
Common mineral worldwide; specimens valued for crystal form, association with other matrix minerals, and strong magnetism
Special Characteristics
Strongly magnetic (lodestone variety exhibits permanent magnetism); frequently forms octahedral crystals
Lore & History
Historically known as lodestone, used in ancient navigation devices like the earliest Chinese compasses. In modern crystal lore, it is associated with grounding, balancing energy, and attracting abundance, though these are traditional beliefs rather than scientific claims.