Magnetite
Magnetite (IMA approved) · Collector Mineral / Industrial Mineral / Ore
Crystal System
Cubic (Isometric); common habits include octahedral crystals, massive, granular, or rounded grains.
Mineral Group
Oxides (Spinel Group)
Chemical Formula
Fe2+Fe3+2O4 (Iron Oxide)
Formation Process
Primarily Igneous (magmatic segregation) or Metamorphic (contact and regional). Can also form via hydrothermal processes.
About This Crystal
An opaque, metallic to sub-metallic black mineral. In this specimen, it appears as a grainy, crystalline mass with a dark grey-black color and a characteristic slight shimmer on fresh surfaces.
Physical Characteristics
Color: Black to brownish-black; Streak: Black; Fracture: Uneven to sub-conchoidal; Specific Gravity: 5.17-5.18; Strongly magnetic.
Optical Properties
Opaque; Refractive Index is not applicable for opaque minerals. Shows no pleochroism or birefringence.
Hardness & Durability
Origin Region
Found globally; notable sources include Kiruna (Sweden), Adirondack Mountains (USA), and various localities in Brazil and South Africa. Typically forms in igneous and metamorphic environments.
Hardness & Durability
Mohs Hardness: 5.5 - 6.5; Brittle tenacity; stable under normal conditions but can oxidize to hematite or limonite over geological time.
Care & Maintenance
Avoid acidic chemicals which can dissolve the surface. Clean with warm soapy water and a soft brush. Keep dry to prevent oxidation/rusting if inclusions of other iron minerals are present.
Rarity & Value
Very common mineral; value is generally low for common specimens but increases for well-formed octahedral crystals or lodestone varieties.
Special Characteristics
Strong magnetism (it is the most magnetic naturally-occurring mineral). A variety known as lodestone acts as a natural magnet.
Lore & History
Historically used for early navigation (compasses) as lodestone. In metaphysical traditions, it is believed to be a grounding stone that aligns the chakras and attracts positive energy or goals.