mineral

Magnetic Sand Grain / Magnetite Pellet

Magnetite (Fe3O4)

Hardness: 5.5-6.5; Color: Black to brownish-black; Luster: Metallic to submetallic; Crystal structure: Isometric (octahedra); Strongly magnetic; Specific Gravity: 5.17-5.18.

Hardness: 5
Color: Black to brownish-black
Luster: Metallic to submetallic

Identified May 26, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5; Color: Black to brownish-black; Luster: Metallic to submetallic; Crystal structure: Isometric (octahedra); Strongly magnetic; Specific Gravity: 5.17-5.18.

Formation & geological history

Formed in igneous or metamorphic rocks as an accessory mineral, often concentrated in sedimentary environments as 'black sand' via weathering and erosion.

Uses & applications

Primary ore of iron; used in heavy media separation, as a pigment, and in industrial magnets.

Geological facts

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

Field identification & locations

Identify by using a magnet; it will be strongly attracted. Often found in beach or river sands where heavy minerals accumulate.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

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

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral