Magnetite (sometimes Lodestone)
Magnetite (IMA-approved mineral species) · Mineral Specimen / Industrial Mineral / Collector Stone
Crystal System
Cubic (Isometric) system, commonly occurring as octahedral or dodecahedral crystals, or in massive, granular forms.
Mineral Group
Oxides; Spinel Group (subgroup: Oxides with multiple cation valencies)
Chemical Formula
Fe2+Fe3+2O4 (Iron Oxide)
Formation Process
Primarily Igneous (magmatic segregation or as an accessory mineral), but also occurs in Metamorphic (regional or contact metamorphism) and Sedimentary (as heavy mineral sand or BIFs) environments.
About This Crystal
An opaque, heavy mineral with a distinctive submetallic to metallic luster. It typically appears iron-black to dark gray with a fairly dull surface unless crystallized into sharp octahedrons.
Physical Characteristics
Color: Iron-black to dark gray; Streak: Black; Fracture: Subconchoidal to uneven; Specific Gravity: 5.1-5.2; Notable for its strong ferrimagnetism; Lacks fluorescence.
Optical Properties
Opaque mineral; under reflected light it is gray with a slight brownish tint. It is isotropic (singly refractive) due to its cubic symmetry and has no pleochroism.
Hardness & Durability
Origin Region
Globally distributed; notable sources include Kiruna (Sweden), Brazil, South Africa, and various locations across North America (e.g., Magnet Cove, Arkansas).
Hardness & Durability
Mohs hardness: 5.5 to 6.5; Toughness: Brittle; Generally stable but can oxidize/rust in moist environments or if exposed to corrosive chemicals.
Care & Maintenance
Clean with a soft brush and warm, dry air; avoid water to prevent oxidation. Keep away from electronic devices, credit cards, and mechanical watches due to its magnetic field.
Rarity & Value
Very common as a mineral; high-quality octahedral crystals are valued by collectors. Generally inexpensive unless presenting as a rare crystallographic habit or large lodestone.
Special Characteristics
Magnetism is its most defining trait; the variety 'Lodestone' acts as a natural magnet. It is often found associated with chlorite, pyrite, and hematite.
Lore & History
Historically used as the first natural compass (Lodestone) by ancient mariners. Metaphysically associated with grounding energy, balancing polarities, and attracting desired outcomes.