mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent grey to brown/black; Luster: Vitreous (glassy); Crystal structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

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

Identified April 15, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent grey to brown/black; Luster: Vitreous (glassy); Crystal structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed through the natural irradiation of aluminum-bearing quartz from surrounding radioactive source rocks within pegmatites or hydrothermal veins across all geological ages.

Uses & applications

Used in ornamental jewelry, as a healing crystal in metaphysical circles, and historically for early sunglasses in 12th century China.

Geological facts

The dark color is caused by free silicon formed from the silicon dioxide by natural irradiation. When it is very dark and opaque, it is often referred to as 'Morion'.

Field identification & locations

Identify in the field by its hardness (scratches glass), lack of cleavage, and translucent grayish 'smoke' color. Commonly found in Brazil, Colorado (USA), and the Swiss Alps.