mineral

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Hardness: 5.5-6.5; Color: Iron-black to dark gray; Luster: Metallic to submetallic; Crystal structure: Isometric (octahedral); Specific Gravity: 5.1-5.2; Streak: Black.

Hardness: 5
Color: Iron-black to dark gray
Luster: Metallic to submetallic

Identified June 24, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5; Color: Iron-black to dark gray; Luster: Metallic to submetallic; Crystal structure: Isometric (octahedral); Specific Gravity: 5.1-5.2; Streak: Black.

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments. Often found as an accessory mineral in igneous rocks like basalt, or in banded iron formations through chemical precipitation and metamorphism.

Uses & applications

Primary ore of iron used for steel production; used as a heavy media for coal separation; also utilized in sandpaper, toners, and magnetic resonance imaging (MRI).

Geological facts

Magnetite is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces called lodestones were used as the first magnetic compasses in history.

Field identification & locations

Identified in the field by its strong magnetism (attracts a magnet), heavy feel, and black streak. Commonly found in river sands as 'black sand' or in large massive deposits.