Magnetite with Goethite
Magnetite var. Lodestone with Goethite inclusions · Mineral Specimen / Industrial Mineral
Crystal System
Cubic (Isometric) for magnetite; Orthorhombic for goethite. Habit is often massive or octahedral.
Mineral Group
Oxides / Spinel Group
Chemical Formula
Fe3O4 (Magnetite) and α-FeOp(OH) (Goethite)
Formation Process
Primarily Igneous (magmatic segregation) or Metamorphic (contact), often found in heavy mineral sands.
About This Crystal
Black to dark grey massive mineral with a semi-metallic to dull luster. Exhibits earthy brownish-yellow goethite oxidation on surface crevices.
Physical Characteristics
Black color, black streak, no cleavage, conchoidal to uneven fracture, specific gravity 5.1-5.2, strongly magnetic.
Optical Properties
Opaque, metallic to sub-metallic luster, isotropic under cross-polarized light (Magnetite).
Hardness & Durability
Origin Region
Commonly sourced from Sweden, Brazil, and South Africa; occurs in banded iron formations and igneous rocks.
Hardness & Durability
Mohs hardness 5.5 - 6.5. Relatively brittle but durable enough for industrial handling.
Care & Maintenance
Avoid acidic cleaners which may dissolve iron; clean with dry cloth; keep dry to prevent further oxidation into rust.
Rarity & Value
Common globally; value is determined by crystallinity or magnetic strength (lodestone status). Usually low cost.
Special Characteristics
Strongly ferrimagnetic; can attract small metal objects or affect a compass needle.
Lore & History
Used by ancient Greek and Chinese mariners as early compasses; traditionally associated with grounding and manifestation.