mineral

Magnetite (Lodestone variety)

Magnetite (Fe3O4)

Hardness: 5.5-6.5 Mohs scale; Color: Black, iron-black to brownish; Luster: Metallic to submetallic; Crystal Structure: Isometric (octahedral); Cleavage: None; Specific Gravity: 5.1-5.2

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

Identified June 30, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5 Mohs scale; Color: Black, iron-black to brownish; Luster: Metallic to submetallic; Crystal Structure: Isometric (octahedral); Cleavage: None; Specific Gravity: 5.1-5.2

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments. Often found as an accessory mineral in igneous rocks or in hydrothermal veins and contact metamorphic deposits.

Uses & applications

Primary ore of iron; used in manufacturing steel, heavy media separation, as magnets, and occasionally in jewelry as beadwork.

Geological facts

It is the most magnetic of all the naturally-occurring minerals on Earth. Naturally magnetized pieces are called lodestones and were used in the first compasses.

Field identification & locations

Identify using a magnet (it will be strongly attracted) and its black streak. Common in banded iron formations and black sands. Look for heavy, dark, metallic-looking rocks.