mineral

Smoky quartz crystal

Quartz, silicon dioxide (SiO₂), likely smoky variety

AI-generated identification · may be incorrect

Transparent to translucent brown-gray crystal with vitreous luster and conchoidal fracture; Mohs hardness 7, trigonal crystal structure, no cleavage, specific gravity about 2.65. The dark, fibrous-looking area may be inclusions or attached matrix.

Identified August 20, 2026More mineral →

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Physical properties

Formation & geological history

Forms in silica-rich hydrothermal veins, pegmatites, and cavities of igneous rocks; smoky coloration commonly results from natural irradiation of aluminum-bearing quartz. Crystals formed across many geological periods, commonly in granitic systems.

Uses & applications

Used as a collector mineral, ornamental stone, and occasional gemstone; quartz is also important in glass, electronics, abrasives, and construction aggregate.

Geological facts

Its apparent dark inclusion could be chlorite, mica, iron oxides, or host-rock material; determining this requires close examination or testing. Faceted smoky quartz is generally durable for jewelry.

Field identification & locations

Identify by glassy luster, hardness sufficient to scratch ordinary glass, lack of cleavage, and six-sided crystal faces when preserved. Common sources include Brazil, Madagascar, Switzerland, the United States, and Spain.