Rock Identifier
Quartz (Smoky/Grey variety) (Silicon Dioxide (SiO2)) — mineral
mineral

Quartz (Smoky/Grey variety)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: Translucent grey to cloudy white. Luster: Vitreous (glassy). Crystal Structure: Hexagonal/Trigonal. Cleavage: Poor/Conchoidal fracture. Specific Gravity: 2.65.

Hardness
7 on the Mohs scale
Color
Translucent grey to cloudy white
Luster
Vitreous (glassy)
Identified More mineral

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Physical properties

Hardness: 7 on the Mohs scale. Color: Translucent grey to cloudy white. Luster: Vitreous (glassy). Crystal Structure: Hexagonal/Trigonal. Cleavage: Poor/Conchoidal fracture. Specific Gravity: 2.65.

Formation & geological history

Formed through the cooling and crystallization of silica-rich magma or hydrothermal veins. It occurs in all geological ages and environments, from igneous plutons to metamorphic schists.

Uses & applications

Used in the production of glass, electronics (piezoelectric properties), abrasives, and as a gemstone for jewelry or metaphysical collecting.

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 by its hardness (it will scratch glass) and its lack of cleavage (it breaks like glass in curved, conchoidal patterns). Commonly found in riverbeds, mountain ranges, and gravel pits.