Magnetite with Quartz/Feldspar Inclusion
Magnetite (Fe3O4) · Mineral Specimen and Meta-Industrial Ore
Crystal System
Cubic (Isometric); typically occurs as octahedral crystals or in massive, granular, or earthy forms.
Mineral Group
Oxides (Spinel Group)
Chemical Formula
Fe2+Fe3+2O4 with trace Silicates (SiO2/KAlSi3O8)
Formation Process
Primarily Igneous (magmatic segregation) or Metamorphic (contact), often found in banded iron formations or hydrothermal veins.
About This Crystal
Dark, opaque metallic to sub-metallic gray base with interspersed translucent to white silicate patches. The luster is dull and earthy in this specific weathered sample.
Physical Characteristics
Color: Iron-black to dark gray; Streak: Black; Fracture: Uneven; Specific Gravity: 5.17-5.18; Strongly Magnetic (Ferrimagnetic property).
Optical Properties
Opaque (not applicable for refractive index); metallic luster reflects light poorly in weathered granular form.
Hardness & Durability
Origin Region
Global; notably Iron Mountain (USA), Kiruna (Sweden), and South Africa in mafic igneous rocks.
Hardness & Durability
Mohs Hardness: 5.5 to 6.5. Brittle tenacity; stable under normal conditions but can oxidize (rust) into limonite over geological time.
Care & Maintenance
Avoid acidic cleaners or ultrasonic baths if porous. Keep dry to prevent oxidation; clean with soft brush and distilled water if necessary.
Rarity & Value
Very common mineral; value is low for granular specimens, higher for well-formed octahedral 'floaters' or loadstone varieties.
Special Characteristics
Extreme magnetism; will attract iron filings or move a compass needle. This specimen shows a weathered 'granular' texture.
Lore & History
Used by Olmecs and Vikings as early navigation lodestones. Traditionally used in crystal healing for 'grounding' energy and alignment of the bio-magnetic field.