mineral

Magnetite (potentially Hematite)

Magnetite (Fe₃O₄)

Hardness: 5.5-6.5; Color: Black to dark gray; Luster: Metallic to submetallic; Crystal Structure: Isometric; Cleavage: None (octahedral parting); Specific Gravity: 5.1-5.2

Hardness: 5
Color: Black to dark gray
Luster: Metallic to submetallic

Identified June 30, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5; Color: Black to dark gray; Luster: Metallic to submetallic; Crystal Structure: Isometric; Cleavage: None (octahedral parting); Specific Gravity: 5.1-5.2

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments. It is often found in banded iron formations (BIFs) and as an accessory mineral in igneous rocks like granite or basalt.

Uses & applications

Primary ore of iron; used in the manufacture of steel, as an abrasive, and sometimes in heavy media separation for coal washing.

Geological facts

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

Field identification & locations

Identify in the field using a magnet; it will be strongly attracted. It will leave a black streak on a porcelain plate (unlike hematite which leaves a reddish-brown streak). Found globally in iron-rich districts.