mineral

Smoky Quartz (with Druzy/Polished Edge)

Smoky Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale. Color: Brownish-grey to black. Luster: Vitreous (glassy). Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

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

Identified April 4, 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: None (conchoidal fracture). Specific Gravity: 2.65.

Formation & geological history

Formed in igneous or metamorphic environments, primarily pegmatites. The smoky color is caused by natural gamma irradiation of trace aluminum impurities within the crystal lattice over millions of years.

Uses & applications

Commonly used in jewelry (faceting), decorative carvings, meditation aids, and as a popular collector's mineral specimen. Some industrial use in electronics, though synthetic quartz is more common.

Geological facts

Smoky quartz is the national gem of Scotland, where it is known as 'Cairngorm' after the Cairngorm Mountains. Extremely dark, opaque specimens are often referred to as 'Morion'.

Field identification & locations

Identify by its smoky transparency and lack of cleavage. In the field, look for it in granitic pegmatites. This specific specimen has been cut and polished on one side to show the dark interior while retaining a druzy (micro-crystalline) surface on the other.

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