mineral

Smoky Quartz

SiO2 (Silicon Dioxide)

Hardness: 7 on Mohs scale; Color: Translucent gray to black; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Translucent gray to black
Luster: Vitreous (glassy)

Identified June 19, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent gray to black; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Formation & geological history

Formed in igneous and metamorphic rocks, particularly pegmatites. The smoky color is caused by natural irradiation of aluminum impurities within the crystal lattice during formation over millions of years.

Uses & applications

Used extensively in jewelry as a gemstone, in crystal healing practices, and as ornamental display specimens for collectors.

Geological facts

Smoky quartz is the national gem of Scotland, where it is known as 'Cairngorm'. Traditionally, it was used in early Chinese sunglasses in the 12th century.

Field identification & locations

Identify by its characteristic 'smoke' color and glass-like clarity. It is common in mountain ranges like the Alps, Brazil, and Madagascar. Collectors look for high transparency and well-defined crystal points.