mineral

Smoky Quartz

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Brownish-grey to black; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Brownish-grey to black
Luster: Vitreous (glassy)

Identified June 23, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Brownish-grey to black; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed in igneous or metamorphic rocks like granite or pegmatites. The dark color is caused by natural irradiation of aluminum-bearing quartz over millions of years.

Uses & applications

Used primarily as a gemstone in jewelry, decorative carvings, and as a popular specimen for mineral collectors and metaphysical practitioners.

Geological facts

Darker, nearly opaque varieties are known as 'Morion.' It is the national gem of Scotland, where it is often referred to as 'Cairngorm' after the mountain range where it is found.

Field identification & locations

Identify in the field by its hexagonal crystal habit, hardness (will scratch glass), and lack of cleavage. Common in granite pockets. Clean with warm soapy water; avoid prolonged exposure to intense heat which can fade the color.