mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Dark brown to greyish-black, translucent to semi-opaque. Luster: Vitreous to resinous. Crystal structure: Trigonal/Hexagonal. Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Dark brown to greyish-black, translucent to semi-opaque
Luster: Vitreous to resinous

Identified July 22, 2026More mineral →

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Physical properties

Formation & geological history

Formed in pegmatites, hydrothermal veins, and metamorphic rocks. The brownish coloration is produced by natural irradiation of aluminum-bearing quartz over geological time.

Uses & applications

Used primarily as gemstone material for jewelry, ornamental carvings, and popular among mineral collectors. Historically used in crystal healing and optical instruments.

Geological facts

Dark, nearly opaque varieties of smoky quartz are known as 'morion'. In 12th-century China, flat panes of smoky quartz were used to make the earliest sunglasses to hide facial expressions in court.

Field identification & locations

Identified by its glass-like luster, hardness (scratches glass), conchoidal fracture, and brownish-black tint. Widely found in granite pegmatites around the world, including Brazil, the US (Colorado), Madagascar, and the Swiss Alps.