mineral

Magnetite with Serpentine

Magnetite (Fe3O4) in Serpentine Matrix

Hardness: 5.5-6.5 (Magnetite); Color: Iron-black to dark grey with greenish matrix; Luster: Metallic to sub-metallic; Crystal structure: Isometric (Octahedral); Specific Gravity: 5.17-5.18.

Hardness: 5
Color: Iron-black to dark grey with greenish matrix
Luster: Metallic to sub-metallic

Identified June 26, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5 (Magnetite); Color: Iron-black to dark grey with greenish matrix; Luster: Metallic to sub-metallic; Crystal structure: Isometric (Octahedral); Specific Gravity: 5.17-5.18.

Formation & geological history

Formed in igneous and metamorphic rocks via hydrothermal alteration or magmatic segregation, often found in serpentinites and banded iron formations across various geological eras.

Uses & applications

Primary ore of iron; used in industrial catalysts, magnetic storage, and as a collector's specimen. Finely ground magnetite is used in water purification and heavy media separation.

Geological facts

Magnetite is the most magnetic of all the naturally-occurring minerals on Earth. Naturally magnetized pieces, called lodestones, were used as the earliest forms of magnetic compasses.

Field identification & locations

Identified in the field by its strong attraction to magnets and its black streak. Common in areas with ultramafic rock outcrops. Collectors should check for high density and magnetic properties.

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