mineral

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities

AI-generated identification · may be incorrect

Hardness: 7 (Mohs); Color: Greyish-brown to black; Luster: Vitreous; Crystal system: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 (Mohs)
Color: Greyish-brown to black
Luster: Vitreous

Identified June 27, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs); Color: Greyish-brown to black; Luster: Vitreous; Crystal system: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Formation & geological history

Forms in igneous rocks like granite and pegmatites, or metamorphic rocks like gneiss. The smoky color is caused by natural irradiation of aluminum-bearing quartz over millions of years.

Uses & applications

Used widely as a gemstone for jewelry, in ornamental carvings, as a healing crystal in metaphysical practices, and as a popular collector specimen.

Geological facts

Dark, nearly opaque black varieties are specifically known as 'Morion'. The color can be deepened through artificial irradiation or removed by heating above 200 degrees Celsius.

Field identification & locations

Identify in the field by its hexagonal crystal habit (if points are present), glass-like luster, and its ability to scratch glass but not topaz. Commonly found in mountainous regions worldwide.