Magnetite (in host rock)
Magnetite (IMA-approved mineral name) · Mineral Specimen / Industrial Mineral
Crystal System
Cubic (Isometric); habit is often octahedral or massive/granular as seen in this matrix-heavy specimen.
Mineral Group
Oxides (Spinel group)
Chemical Formula
Fe2+Fe3+2O4
Formation Process
Igneous (crystallizing from cooling magma) or Metamorphic (contact metamorphism and regional metamorphism).
About This Crystal
The specimen is a dark gray to black, opaque mineral with a dull to sub-metallic luster. It appears granular and embedded within a lithic matrix, showing a rough, uneven texture with small reflective flecks.
Physical Characteristics
Color: Iron-black to dark gray; Streak: Black; Cleavage: None (distinct octahedral parting); Fracture: Uneven to sub-conchoidal; Specific Gravity: 5.17–5.18; Magnetism: Strongly magnetic.
Optical Properties
Opaque; Refractive Index: N/A (metallic/sub-metallic); Isotropic; No pleochroism or dispersion. Exhibits no optical phenomena such as chatoyancy.
Hardness & Durability
Origin Region
Kiruna, Sweden; Iron Springs, Utah, USA; and various locations in Brazil and South Africa. Typically found in igneous and metamorphic environments.
Hardness & Durability
Mohs hardness: 5.5–6.5; Toughness: Brittle; Stable under normal conditions but can oxidize to hematite or goethite over long periods of moisture exposure.
Care & Maintenance
Keep dry to prevent oxidation (rusting). Clean with a soft dry cloth; avoid ultrasonic cleaners if the matrix is porous. Store separately from softer stones or magnets that might affect its polarity.
Rarity & Value
Common; Value is generally low for industrial-grade specimens, though well-formed octahedral crystals can command higher prices from collectors.
Special Characteristics
Ferrimagnetic; some specimens (lodestone) act as natural magnets. In this form, it exhibits subtle metallic glints when rotated under light.
Lore & History
Historically used as 'lodestone' for early navigation compasses. In traditional lore, it is thought to be a grounding stone and used in practices intended to 'attract' energy or manifest goals.