mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Brown to black, translucent to transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Brown to black, translucent to transparent
Luster: Vitreous (glassy)

Identified March 11, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous and metamorphic rocks, particularly pegmatites and hydrothermal veins. The smoky color is produced when natural radiation from surrounding rocks activates aluminum impurities within the quartz crystal lattice.

Uses & applications

Commonly used in jewelry (faceting), carvings, and metaphysical collecting. Also used in industry as a source of high-purity silica for electronics and solar panels.

Geological facts

Smoky quartz is the national gem of Scotland, where it is known as 'Cairngorm.' Some of the darkest, nearly opaque varieties are referred to as 'Morion.'

Field identification & locations

Identify by its smoky translucence, lack of cleavage, and ability to scratch glass. In the field, it is commonly found in granitic mountains such as the Swiss Alps or the Pikes Peak region of Colorado.