mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite (Fe2O3·nH2O) inclusions

Hardness: 7 on Mohs scale; Color: Brown, red, orange, or yellowish due to iron oxides; Luster: Vitreous to dull; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Brown, red, orange, or yellowish due to iron oxides
Luster: Vitreous to dull

Identified June 18, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins or sedimentary environments where iron-rich fluids interact with quartz crystals. This specimen often appears as iron-stained rock crystal or macrorocrystalline quartz found in iron-heavy soil or pegmatites.

Uses & applications

Primarily for mineral collecting, lapidary use (tumbled stones), and occasionally used in metaphysical practices for its grounding properties.

Geological facts

Also known as Eisenkiesel or Iron Quartz, the staining can be either on the surface or included within the crystal lattice. Iron oxides like hematite and goethite are the primary reason for the earthy brown and orange tones.

Field identification & locations

Identify by its hardness (will scratch glass), hexagonal crystal habit (if preserved), and the characteristic orange-brown staining that does not wash off with water. Common in areas with red clay soils or iron ore deposits.

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

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Nephrite Jade

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Mineral/Rock

Banded Gneiss (River Rock/Pebble)

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

Metamorphic Rock

Green Apatite on Albite

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mineral