mineral

Magnetite / Iron Ore (likely Hematite-Magnetite mix)

Magnetite (Fe3O4)

Hardness: 5.5-6.5; Color: Black to dark brownish-gray; Luster: Metallic to sub-metallic; Crystal structure: Isometric/Octahedral; Cleavage: None; Specific Gravity: 5.1-5.2

Hardness: 5
Color: Black to dark brownish-gray
Luster: Metallic to sub-metallic

Identified June 12, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 5.5-6.5; Color: Black to dark brownish-gray; Luster: Metallic to sub-metallic; Crystal structure: Isometric/Octahedral; Cleavage: None; Specific Gravity: 5.1-5.2

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments. Often found in banded iron formations (BIFs) dating back over 2 billion years, or as magmatic segregations.

Uses & applications

Primary ore of iron for steel production; used as a heavy media for coal washing, as a pigment (ochre), and in magnetic storage media.

Geological facts

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

Field identification & locations

Identify in the field using a magnet; it is highly attracted to them. A streak test on unglazed porcelain will leave a black streak (unlike the reddish-brown streak of hematite). Common in iron-rich mining districts like the Mesabi Range in Minnesota.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

metamorphic