mineral

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities

AI-generated identification · may be incorrect

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

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

Identified July 13, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in igneous and metamorphic rocks, particularly pegmatites and hydrothermal veins. The color comes from natural gamma radiation that activates aluminum impurities within the quartz lattice.

Uses & applications

Commonly used in jewelry (facets and beads), metaphysical practices, and as decorative collector specimens.

Geological facts

Unlike many dark minerals, smoky quartz remains translucent even in deep shades. It is the national gem of Scotland, where it is known as Cairngorm.

Field identification & locations

Identified by its transparency and distinct smoky grey-brown color. Found globally in granitic terrains. Collectors look for clarity and well-defined crystal terminations.