mineral

Magnetite

Magnetite (Fe3O4)

Hardness: 5.5-6.5; Color: Black to brownish-black; Luster: Metallic to submetallic; Crystal structure: Isometric (octahedral); Cleavage: None/Indistinct; Specific Gravity: 5.17-5.18

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

Identified June 22, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5; Color: Black to brownish-black; Luster: Metallic to submetallic; Crystal structure: Isometric (octahedral); Cleavage: None/Indistinct; Specific Gravity: 5.17-5.18

Formation & geological history

Found in igneous, metamorphic, and sedimentary rocks. Formed through magmatic segregation, contact metamorphism, or as heavy mineral sand deposits. It is the most magnetic of all naturally occurring minerals on Earth.

Uses & applications

Primary ore of iron; used in the production of steel, heavy media separation, as a pigment (ochre), and in early navigation (lodestones).

Geological facts

Naturally magnetized pieces of magnetite are called lodestones and were used as the first magnetic compasses. It is a ferrimagnetic mineral containing both iron(II) and iron(III) oxides.

Field identification & locations

Identify in the field by its strong attraction to magnets, black streak on a porcelain plate, and high density. Commonly found in banded iron formations and beach sands in volcanic regions.