mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: Brownish-grey, translucent to nearly opaque. Luster: Vitreous (glassy). Crystal Structure: Hexagonal (trigonal). Cleavage: None, exhibits conchoidal fracture. Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Brownish-grey, translucent to nearly opaque
Luster: Vitreous (glassy)

Identified April 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous and metamorphic rocks, particularly pegmatites and hydrothermal veins. The color is caused by natural irradiation of aluminum-bearing quartz over millions of years within the Earth's crust.

Uses & applications

Commonly used in jewelry as a gemstone, in decorative carvings, and in metaphysical practices. Historically used for one of the first known pairs of sunglasses in 12th century China.

Geological facts

Smoky quartz can range from a light yellowish-brown to a brown so dark it looks black (this variety is known as 'Morion'). The color can be artificially induced by lab-irradiating clear quartz.

Field identification & locations

Identify in the field by its distinct translucent brown/smoke color, lack of cleavage, and ability to scratch glass easily. Common locations include the Swiss Alps, Brazil, and Pikes Peak, Colorado.