mineral

Quartz Crystal (Smoky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to grey-brown/smoky; Luster: Vitreous; Crystal System: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Clear to grey-brown/smoky
Luster: Vitreous

Identified July 9, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Clear to grey-brown/smoky; Luster: Vitreous; Crystal System: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal solutions or cooling magma within igneous rocks like granite. Smoky varieties often result from natural gamma radiation exposure during long geological periods.

Uses & applications

Used in electronics for its piezoelectric properties, glass manufacturing, jewelry, and widely collected as a metaphysical or display specimen.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. This specimen shows 'double termination' where points form at both ends, which is relatively rare compared to single-pointed crystals.

Field identification & locations

Look for six-sided prisms with pyramid-like terminations. It can scratch glass and does not react to acid. Common worldwide, with famous deposits in the Swiss Alps, Brazil, and Arkansas.