mineral

Magnetite (Lodestone)

Iron(II,III) oxide (Fe3O4)

Hardness: 5.5-6.5; Color: black to brownish-black; Luster: metallic to submetallic; Crystal structure: isometric; Cleavage: none; Specific gravity: 5.17-5.18. It is highly magnetic.

Hardness: 5
Color: black to brownish-black
Luster: metallic to submetallic

Identified June 17, 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; Cleavage: none; Specific gravity: 5.17-5.18. It is highly magnetic.

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments. Often found as a primary mineral in mafic igneous rocks through magmatic segregation. It can be billions of years old or relatively recent depending on the host rock formation.

Uses & applications

The primary ore of iron for steel manufacturing; also used in water filtration, heavy media separation, and as a material for magnetic recording. Natural magnets (lodestones) are collector items.

Geological facts

Magnetite is the most magnetic of all naturally occurring minerals on Earth. Its magnetic properties once helped early navigators create the first compasses. Highly sensitive birds/animals are believed to have magnetite in their brains for navigation.

Field identification & locations

Identified in the field by its black color, black streak, and strong attraction to a magnet. Commonly found in heavy mineral sands and as accessory minerals in granite or basalt.