mineral

Ferruginous Quartz (Red Quartz)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale), Color: Rusty red to yellowish-brown, Luster: Vitreous to waxy, Crystal structure: Trigonal/Hexagonal, Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Identified July 19, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Rusty red to yellowish-brown, Luster: Vitreous to waxy, Crystal structure: Trigonal/Hexagonal, Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Formation & geological history

Formed through hydrothermal processes or silica-rich fluid precipitation where iron oxides like hematite or limonite are present. Often found as water-worn pebbles in riverbeds or glacial deposits.

Uses & applications

Used primarily for ornamental purposes, lapidary work (tumbling/cabochons), and as a collector's specimen for its unique coloration.

Geological facts

The red color is not part of the quartz crystal lattice but is caused by microscopic inclusions or coatings of iron oxides. These are sometimes called 'Hematoid Quartz' or 'Eisenkiesel' in German.

Field identification & locations

Identify by its hardness (will scratch glass), translucent to opaque appearance, and the presence of internal red staining or veining. Commonly found in gravel pits and beaches worldwide.