mineral

Magnetite

Magnetite (Fe3O4)

AI-generated identification · may be incorrect

Color: Iron-black to dark gray; Luster: Metallic to submetallic; Hardness: 5.5 - 6.5; Special property: Strong magnetism; Crystal structure: Isometric/Octahedral; Specific Gravity: 5.1 - 5.2

Hardness: 5
Color: Iron-black to dark gray
Luster: Metallic to submetallic

Identified July 14, 2026More mineral →

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Physical properties

Color: Iron-black to dark gray; Luster: Metallic to submetallic; Hardness: 5.5 - 6.5; Special property: Strong magnetism; Crystal structure: Isometric/Octahedral; Specific Gravity: 5.1 - 5.2

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments. Often found as an accessory mineral in igneous rocks like basalt and granite, or as massive beds in metamorphic banded iron formations.

Uses & applications

The most important ore of iron. Used in industrial processes as a heavy medium for coal washing, as a pigment (mars black), and historically for early compasses (lodestones).

Geological facts

Magnetite is the most magnetic of all the naturally-occurring minerals on Earth. Pieces of magnetite that act as natural magnets are called lodestones and were used by Vikings for navigation.

Field identification & locations

The easiest field identification is its strong attraction to a magnet. It has a black streak. Found globally, specifically in huge deposits in Kiruna, Sweden, and the Lake Superior region of North America.