mineral

Magnetite (Lodestone variety)

Magnetite (Fe3O4)

Hardness: 5.5-6.5 Mohs scale; Color: Black, iron-black to dark gray; Luster: Metallic to submetallic; Crystal Structure: Octahedral/Cubic; Cleavage: None; Specific Gravity: 5.1-5.2

Hardness: 5
Color: Black, iron-black to dark gray
Luster: Metallic to submetallic

Identified April 27, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5 Mohs scale; Color: Black, iron-black to dark gray; Luster: Metallic to submetallic; Crystal Structure: Octahedral/Cubic; Cleavage: None; Specific Gravity: 5.1-5.2

Formation & geological history

Formed in high-temperature igneous and metamorphic rocks via magmatic crystallization or hydrothermal processes. Also found in sedimentary banded iron formations.

Uses & applications

Primary ore of iron; used in heavy media separation, steel production, water filtration, and occasionally as healing stones in folk medicine.

Geological facts

Magnetite is the most magnetic of all the naturally-occurring minerals on Earth. Some varieties, known as lodestone, act as natural magnets and were used to create the first compasses.

Field identification & locations

Identify in the field using a handheld magnet (it will strongly attract) and its black streak on a porcelain plate. Found globally in places like Sweden, South Africa, and the USA.