mineral
Smoky Quartz
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 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)
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Physical properties
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.
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.
