mineral

Magnetite

Magnetite (Fe3O4)

Hardness: 5.5-6.5 on Mohs scale; Color: Black to silvery gray; Luster: Metallic to submetallic; Crystal Structure: Isometric/Octahedral; Cleavage: None/Indistinct; Specific Gravity: 5.1-5.2

Hardness: 5
Color: Black to silvery gray
Luster: Metallic to submetallic

Identified April 9, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5 on Mohs scale; Color: Black to silvery gray; Luster: Metallic to submetallic; Crystal Structure: Isometric/Octahedral; Cleavage: None/Indistinct; Specific Gravity: 5.1-5.2

Formation & geological history

Mostly occurs in igneous and metamorphic rocks as an accessory mineral. Formed through crystallization from cooling magma or during contact/regional metamorphism of iron-rich sediments.

Uses & applications

Primary ore of iron. Used in industrial processes as a heavy medium for coal washing, in chemical industries, and as an abrasive. In jewelry, it is sometimes used as magnetic beads.

Geological facts

Magnetite is the most magnetic naturally occurring mineral on Earth. In the past, naturally magnetized pieces called 'lodestones' were used as the first primitive magnetic compasses for navigation.

Field identification & locations

The most reliable field identification is its strong attraction to a magnet. It also leaves a characteristic black streak when rubbed on a porcelain plate and has a heavy feel relative to its size.