mineral

Magnetite

Iron(II,III) oxide (Fe3O4)

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

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

Identified June 26, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in igneous and metamorphic environments through crystallization from a melt or by hydrothermal replacement. It is often found in contact metamorphic zones and as a detrital mineral in beach sands.

Uses & applications

The primary ore of iron; used in heavy media separation, steel production, and as a natural magnet (lodestone) for early navigation.

Geological facts

Magnetite is the most magnetic of all the naturally-occurring minerals on Earth. It was used by ancient mariners to create the first compass needles.

Field identification & locations

Identified by its strong attraction to magnets and its black streak on a porcelain plate. It is commonly found in banded iron formations and heavy sand deposits.