Quartz (Iron-stained)

Physical Properties

Hardness: 7 (Mohs scale), Color: Tan to brownish-yellow due to iron oxide staining, Luster: Vitreous to greasy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & Geological History

Formed from hydrothermal veins, cooling of magma in igneous rocks, or through recrystallization in metamorphic environments. This specimen shows surface weathering and iron deposition common in oxidized soil environments.

Uses & Applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as a common landscaping or building stone. Higher quality specimens are used in jewelry and crystal collecting.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is colorless; variations like this tan/yellow specimen occur when iron and other minerals leach into fractures or coat the surface.

Field Identification & Locations

Identify in the field by its inability to be scratched by a steel knife (7 hardness) and its lack of cleavage (it breaks in curved, glass-like patterns). It is ubiquitous and can be found in almost any geological setting worldwide.

Identified on: 4/22/2026

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