mineral

Quartz (Smoky/Milky variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Tan to brownish-white; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Tan to brownish-white
Luster: Vitreous to greasy

Identified July 16, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Tan to brownish-white; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. This specimen likely weathered out of a larger host rock like granite or pegmatite.

Uses & applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, and as a collector specimen or landscaping stone.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is chemically and physically very resistant to weathering, which is why it often remains as pebbles after other minerals have eroded away.

Field identification & locations

Identify by its hardness (cannot be scratched by a steel knife) and lack of cleavage. Common in river beds, beaches, and mountainous regions worldwide.