mineral

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Hardness: 5.5-6.5 on Mohs scale; Color: Black to silvery gray; Luster: Metallic to sub-metallic; Crystal structure: Isometric (octahedral); Specific gravity: 5.17-5.18; Magnetic property: Strongly magnetic.

Hardness: 5
Color: Black to silvery gray
Luster: Metallic to sub-metallic

Identified July 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments. It often occurs as a primary mineral in mafic igneous rocks through magmatic segregation and in banded iron formations from the Precambrian era.

Uses & applications

Primary ore for iron and steel production; used as a heavy media for coal washing, in magnetic storage media, and as a mineral specimen for collectors.

Geological facts

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

Field identification & locations

Check for strong attraction to a magnet. It has a black streak when rubbed on a porcelain plate. Common in areas with volcanic activity or ancient sedimentary iron beds like the Mesabi Range in the USA.