Magnetite (in Host Rock)
Magnetite (Iron Oxide) · Mineral Specimen / Industrial Ore
Crystal System
Cubic (Isometric); habit is typically octahedral or granular/massive
Mineral Group
Oxides (Spinel Group)
Chemical Formula
Fe2+Fe3+2O4
Formation Process
Igneous (magmatic segregation) or Metamorphic (contact or regional metamorphism of iron-rich sediments).
About This Crystal
An opaque, metallic to sub-metallic dark grey or black mineral embedded in a lighter grey silicate matrix. Appears granular with some reddish-brown iron staining (limonite/hematite) on the surface.
Physical Characteristics
Color: Iron-black to dark grey; Streak: Black; Cleavage: None (octahedral parting); Fracture: Uneven to subconchoidal; Gravity: 5.17; Strongly magnetic.
Optical Properties
Opaque; metallic to dull luster; non-pleochroic; isotropic due to cubic symmetry.
Hardness & Durability
Origin Region
Global; significant deposits in Kiruna (Sweden), South Africa, and the Adirondack Mountains (USA).
Hardness & Durability
Mohs hardness: 5.5 - 6.5; brittle toughness; high chemical stability but prone to oxidation (rusting) in moist environments.
Care & Maintenance
Keep dry to prevent oxidation. Clean with a soft brush and avoid harsh chemicals. Store away from electronic devices because of its magnetic field.
Rarity & Value
Common; primary ore of iron. Value is low for raw specimens but higher for well-formed octahedral 'Lodestone' crystals.
Special Characteristics
Strongly ferrimagnetic; some specimens act as natural magnets (Lodestone). Often exhibits a granular texture in matrix.
Lore & History
Historically used by early mariners for navigation as the first compasses (Lodestone). Traditionally believed to be a 'grounding' stone in crystal healing due to its magnetic pull.