mineral

Quartz with Iron Staining

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Transparent to milky white with reddish-brown staining, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified June 15, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. The reddish-brown staining is caused by iron oxide (limonite or hematite) leaching into cracks from surrounding soil or water over geological time.

Uses & applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, and as decorative gravel. Lower grade specimens like this are primarily for amateur collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Historically, stained quartz was sometimes mistaken for gold-bearing ore when the iron staining appeared yellowish.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and translucent 'waxy' appearance. This specimen specifically shows common surface weathering found in many global environments.