mineral

Ferruginous Quartz / Iron-Stained Quartz

Silicon Dioxide with Iron Oxide impurities (SiO2 + Fe2O3)

AI-generated identification · may be incorrect

Hardness of 7 on the Mohs scale, color ranges from yellow, brown, to reddish-brown due to iron staining, vitreous to greasy luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of approximately 2.65.

Identified August 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins, pegmatites, or sedimentary environments where quartz crystals or masses have been exposed to iron-bearing groundwaters that stain and coat the exterior and fractures over thousands to millions of years.

Uses & applications

Used primarily as decorative landscape rocks, mineral specimen collecting, lapidary arts, and sometimes tumbled for gemstone jewelry.

Geological facts

The reddish-brown coloration is typically caused by hematite or goethite staining. Quartz is one of the most abundant minerals on Earth's continental crust.

Field identification & locations

Can be identified in the field by its high hardness (scratches glass), lack of cleavage, and characteristic rusty iron staining. Common worldwide wherever quartz veins weather in iron-rich host rocks.