mineral

Quartz (Smoky/Milky variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Tan to light brown; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Tan to light brown
Luster: Vitreous (glassy)

Identified May 9, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Tan to light brown; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich magma or from hydrothermal veins. It can be found in almost all geological environments and across all geological ages.

Uses & applications

Common varieties are used in glass making, electronics (piezoelectric properties), abrasives, and as semi-precious gemstones in jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Smoky quartz gets its color from natural irradiation of aluminum impurities within the crystal lattice.

Field identification & locations

Identify in the field by its ability to scratch glass and lack of cleavage. This specific specimen appears to be a water-worn or weathered fragment found in many gravel beds or river deposits globally.