Magnetite
Magnetite (Iron Oxide) · Mineral Specimen / Industrial Mineral
Crystal System
Cubic (Isometric); commonly occurs in octahedral crystals, massive, or granular habits.
Mineral Group
Oxides (Spinel group)
Chemical Formula
Fe2+Fe3+2O4
Formation Process
Primarily Igneous (magmatic segregation) or Metamorphic (contact and regional); also found in hydrothermal veins and as detrital grains in sedimentary 'black sands'.
About This Crystal
Opaque mineral with a metallic to sub-metallic luster. Appears iron-black to dark grey with a somewhat grainy or crystalline surface. Often associated with yellowish-brown oxidation (limonite/goethite) on the surface matrix.
Physical Characteristics
Color: Iron-black; Streak: Black; Cleavage: None (distinct parting on {111}); Fracture: Subconchoidal to uneven; Specific Gravity: 5.17-5.18; Tenacity: Brittle; Magnetism: Strongly magnetic.
Optical Properties
Opaque; metallic luster; shows no pleochroism or birefringence as it is isotropic (cubic system).
Hardness & Durability
Origin Region
Global; notable sources include Kiruna (Sweden), Adirondack Mountains (USA), and various localities in Brazil and South Africa. Often found in igneous and metamorphic rocks.
Hardness & Durability
Mohs hardness: 5.5 - 6.5. Relatively durable but brittle; susceptible to rusting if exposed to moisture and oxygen over long periods.
Care & Maintenance
Keep dry to prevent oxidation; clean with a soft dry brush; avoid ultrasonic cleaners which may agitate internal fractures; store away from other sensitive magnets or electronic devices.
Rarity & Value
Common; value is generally low for massive specimens, though well-formed octahedral crystals or 'Lodestone' (naturally magnetized variety) specimens command higher prices for collectors.
Special Characteristics
Strongly ferrimagnetic; some specimens (Lodestone) act as natural permanent magnets. Can exhibit interesting surface oxidation patinas.
Lore & History
Historically used as the first compasses (lodestones) by early navigators. In metaphysical lore, it is believed to be a 'grounding stone' that aligns the chakras and attracts positive energy or goals due to its magnetic nature.