Magnetite (in matrix)
Magnetite · Mineral Specimen / Industrial Mineral
Crystal System
Cubic (Isometric); habit is typically octahedral, dodecahedral, or massive granular
Mineral Group
Oxides (Spinel Group)
Chemical Formula
Fe2+Fe3+2O4
Formation Process
Primarily Igneous (magmatic segregation) and Metamorphic (contact or regional metamorphism); also found as detrital grains in black sands
About This Crystal
The specimen shows a dark gray to black, opaque mineral with a submetallic to metallic luster embedded in a brownish, weathered matrix. The surface appears granular and shows signs of oxidation/weathering.
Physical Characteristics
Color: Iron-black to dark gray. Streak: Black. Cleavage: None (distinct parting on {111}). Fracture: Uneven to subconchoidal. Specific Gravity: 5.17-5.18. Highly magnetic.
Optical Properties
Opaque in hand specimen. Refractive index is not applicable as it is opaque. Generally isotropic under reflected light with no pleochroism.
Hardness & Durability
Origin Region
Notable sources include Kiruna (Sweden), Lobatse (South Africa), and the Adirondack Mountains (USA); found in igneous, metamorphic, and sedimentary rocks
Hardness & Durability
Mohs hardness 5.5 to 6.5. Toughness is brittle. Stable under normal conditions but can oxidize to hematite or goethite over geological time.
Care & Maintenance
Clean with a soft brush and warm soapy water. Avoid acidic chemicals which can dissolve iron oxides. Keep dry to prevent rust; store away from electronic devices due to magnetic properties.
Rarity & Value
Common mineral. Value is generally low for massive specimens, though well-formed octahedral crystals are prized by collectors. Mostly valued industrial as an iron ore.
Special Characteristics
Strongly magnetic (Ferrimagnetism). Some specimens may act as natural magnets (Lodestone).
Lore & History
Historically used in early compasses (Lodestone) for navigation. Metaphysically associated with grounding, manifestation, and balancing polarities; linked to the Root Chakra.