mineral

Magnetite (likely with weathered Limonite/Hematite)

Magnetite (Fe3O4) with iron oxide weathering

AI-generated identification · may be incorrect

Hardness: 5.5-6.5 on Mohs scale; Color: Black to dark gray with yellowish-brown oxidation; Luster: Metallic to sub-metallic/dull; Crystal structure: Isometric (octahedron); Cleavage: None (parting); Specific gravity: 5.17-5.18

Hardness: 5
Color: Black to dark gray with yellowish-brown oxidation
Luster: Metallic to sub-metallic/dull

Identified March 20, 2026More mineral →

Explore Magnetite (likely with weathered Limonite/Hematite) in the encyclopedia →

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Physical properties

Formation & geological history

Formed through igneous activity in magmatic segregations, contact metamorphism, or as a heavy mineral sand in sedimentary deposits. It is commonly found in banded iron formations (BIFs) dating back to the Precambrian era.

Uses & applications

Primary ore of iron; used in the manufacturing of steel, as a heavy media for coal washing, as an abrasive, and rarely as a gemstone (magnetic jewelry).

Geological facts

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

Field identification & locations

Identify in the field using a handheld magnet; it will be strongly attracted. Look for the black streak on a porcelain plate and the heavy density. Common in mining districts of the Adirondacks (USA), Kiruna (Sweden), and Western Australia.