mineral

Quartz (Iron-stained or Ferruginous)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to reddish-orange (due to iron oxidation); Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to reddish-orange (due to iron oxidation)
Luster: Vitreous to greasy

Identified April 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes where silica-rich fluids crystallize in veins or cavities within host rocks. The reddish-brown tint comes from iron-rich sediments or fluids leaching into the quartz during or after formation.

Uses & applications

Used primarily as decorative stone, in lapidary work, and sometimes as a source of silica for glassmaking. High-quality clusters are valued in crystal collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained quartz is often found in 'vugs' or pockets where groundwater has deposited hematite or goethite over long geological periods.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel) and its lack of cleavage. Look for it in quartz veins protruding from eroded metamorphic or igneous terrain. It is often found near the surface in rocky outcroppings.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

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metamorphic

Nephrite Jade

Nephrite

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