mineral

Smoky Quartz Cluster

Smoky Quartz (Silicon Dioxide - SiO2)

Hardness: 7 on the Mohs scale. Color: Translucent grayish-brown to blackish (smoky appearance). Luster: Vitreous (glass-like). Crystal structure: Trigonal/Hexagonal prism. Cleavage: Indistinct/Conchoidal fracture. Specific gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Translucent grayish-brown to blackish (smoky appearance)
Luster: Vitreous (glass-like)

Identified March 7, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the natural irradiation of aluminum-bearing clear quartz within igneous or metamorphic rocks, typically in pegmatites or hydrothermal veins. Ages vary widely based on the host rock formation.

Uses & applications

Used in gemstone jewelry, ornamental carvings, and widely collected as mineral specimens. In industry, quartz is used in electronics and glass-making, though smoky varieties are preferred for aesthetics.

Geological facts

The 'smoky' color is caused by free silicon formed from silicon dioxide by natural radiation. Historically, the first 'sunglasses' were made from flat panes of smoky quartz in 12th-century China.

Field identification & locations

Identify by its hexagonal crystal points, inability to be scratched by steel, and distinct smoky translucency. Commonly found in Brazil, the Swiss Alps, and many parts of the United States (notably Colorado).

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