mineral

Quartz (Smoky/Milky variant)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Brownish-tan to translucent grey; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Brownish-tan to translucent grey
Luster: Vitreous to greasy

Identified May 3, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Brownish-tan to translucent grey; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich magma or from hydrothermal veins. This specimen shows signs of weathering and iron-oxide staining, likely formed hundreds of millions of years ago in a continental crust environment.

Uses & applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, and as a decorative collector's item or gemstone (smoky quartz).

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear, but impurities like iron or radiation exposure create the brown/yellow colors seen in this specimen.

Field identification & locations

Identify by its hardness (it will scratch glass) and lack of cleavage planes. Found globally in almost all geological environments. This specific specimen appears to be a common field find known as 'bull quartz' with surface staining.