mineral

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Hardness: 5.5-6.5 on Mohs scale; Color: Black to brownish-black; Luster: Metallic to submetallic; Crystal Structure: Isometric; Cleavage: None/Indistinct; Specific Gravity: 5.1-5.2 (notably heavy)

Hardness: 5
Color: Black to brownish-black
Luster: Metallic to submetallic

Identified March 1, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5 on Mohs scale; Color: Black to brownish-black; Luster: Metallic to submetallic; Crystal Structure: Isometric; Cleavage: None/Indistinct; Specific Gravity: 5.1-5.2 (notably heavy)

Formation & geological history

Commonly forms in igneous and metamorphic rocks through magmatic segregation or hydrothermal processes; also found in banded iron formations and as heavy mineral sand in sedimentary environments

Uses & applications

Primary ore of iron for steel manufacturing; used in heavy media separation, as magnets, and historically as lodestones for navigation

Geological facts

Magnetite is the most magnetic of all the naturally-occurring minerals on Earth; natural magnets are called lodestones and were used in the first compasses

Field identification & locations

Identified in the field by its strong attraction to a magnet and its black streak; often found in dark-colored igneous rocks like basalt or as concentrated black sand on beaches