mineral

Smoky quartz

Quartz (SiO₂), brown to gray smoky variety

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent smoky-brown color, vitreous luster, conchoidal fracture, and hexagonal crystal structure. It lacks cleavage and has specific gravity near 2.65; the specimen appears naturally fractured or partly crystalline.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Forms in hydrothermal veins, pegmatites, and cavities of igneous rocks when trace aluminum and natural irradiation color quartz. Crystals occur from many geological ages, commonly in Precambrian to younger granitic environments.

Uses & applications

Used as an ornamental and collectible mineral, with transparent pieces cut as gemstones; massive material may be used decoratively. It has little industrial value compared with ordinary quartz.

Geological facts

Smoky coloration ranges from pale gray to nearly black and can fade with strong heat or sunlight. Very dark material is sometimes called morion.

Field identification & locations

Identify by its glassy luster, hardness sufficient to scratch steel or glass, conchoidal fracture, and absence of cleavage; common localities include Brazil, Switzerland, Scotland, Colorado, and Maine. The image may also contain inclusions or associated feldspar/mica.