Magnetite Orthorthotropic Rock

Physical Properties

Hardness: 5.5-6.5 on Mohs scale. Color: Black to brownish-black. Luster: Metallic to submetallic. Crystal structure: Isometric (octahedral). Specific gravity: 5.17-5.18. Streak: Black.

Formation & Geological History

Formed in igneous, metamorphic, and sedimentary environments. Typically occurs as a primary mineral in igneous rocks like basalt/gabbro, or through contact metamorphism. Can be billions of years old.

Uses & Applications

Primary ore of iron. Used in steel production, as a heavy media for coal washing, and in its lodestone form for early navigation. Also used in pigments and medicinal research.

Geological Facts

Magnetite is the most magnetic mineral on Earth. Naturally magnetized pieces called lodestones were used to create the first compasses. It is also found in the brains of some animals to help them navigate.

Field Identification & Locations

Identified in the field by its strong magnetism (will attract a neodymium magnet), black streak, and high density. Commonly found in heavy sand deposits, banded iron formations, and volcanic terrains.

Identified on: 4/20/2026

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