mineral

Magnetite Ore

Magnetite (Fe3O4)

Hardness: 5.5-6.5; Color: Iron-black to dark grey; Luster: Metallic to submetallic; Crystal structure: Isometric (often octahedral); Specific gravity: 5.1-5.2; Strongly magnetic.

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

Identified July 13, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5; Color: Iron-black to dark grey; Luster: Metallic to submetallic; Crystal structure: Isometric (often octahedral); Specific gravity: 5.1-5.2; Strongly magnetic.

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments. Typically occurs as an accessory mineral in igneous rocks or as a contact metamorphic product. Often found in river sands and beach deposits as heavy mineral concentrations.

Uses & applications

Primary ore of iron; used in the manufacturing of steel, as a pigment in paints (burnt umber), and in the chemical industry as a catalyst.

Geological facts

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

Field identification & locations

Identified in the field by its dark color, metallic luster, and strong attraction to magnets. Use a streak plate (should leave a black streak) and check for magnetism with a compass or small magnet.