mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Translucent grey to dark brown/black. Luster: Vitreous (glassy). Crystal Structure: Hexagonal/Trigonal. No cleavage; conchoidal fracture. Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Translucent grey to dark brown/black
Luster: Vitreous (glassy)

Identified July 5, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: Translucent grey to dark brown/black. Luster: Vitreous (glassy). Crystal Structure: Hexagonal/Trigonal. No cleavage; conchoidal fracture. Specific Gravity: 2.65.

Formation & geological history

Forms in igneous rocks like granite through the crystallization of magma or in hydrothermal veins. The characteristic smoky color is caused by natural irradiation of trace aluminum impurities within the crystal lattice.

Uses & applications

Commonly used in jewelry as a gemstone, in decorative carvings, as a healing crystal in metaphysical circles, and occasionally in the manufacture of glass and electronics if of high purity.

Geological facts

The dark brown to black varieties are often called 'Morion'. In ancient China, smoky quartz was used to make the first recorded sunglasses to hide the expressions of judges in courts.

Field identification & locations

Look for a translucent grey-brown color and a glassy luster. Unlike glass, it will scratch common steel tools. It is frequently found in pegmatites and mountainous regions globally.