mineral

Smoky Quartz Cluster

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Gray to translucent brown; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None/Conchoidal fracture.

Hardness: 7 on Mohs scale
Color: Gray to translucent brown
Luster: Vitreous (glassy)

Identified April 19, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Gray to translucent brown; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None/Conchoidal fracture.

Formation & geological history

Forms in igneous rocks like pegmatites or in hydrothermal veins through slow cooling of silica-rich fluids. The smoky color is caused by natural radiation from surrounding rocks acting on aluminum impurities.

Uses & applications

Commonly used for ornamental specimens, metaphysical healing collections, and occasionally faceted for jewelry or used in watches/electronics for its piezoelectric properties.

Geological facts

Unlike many dark minerals, the color in smoky quartz is not due to its chemistry but to structural changes caused by exposure to radiation over millions of years.

Field identification & locations

Identify by its hexagonal crystal points, inability to be scratched by steel, and transition from clear to grayish-brown. Commonly found in mountainous regions like the Alps, Brazil, and the USA (Colorado).