mineral

Smoky quartz crystal (tentative)

Quartz, silicon dioxide (SiO₂), likely smoky variety

AI-generated identification · may be incorrect

Translucent brown to gray with a vitreous luster and apparent crystal faces; quartz has Mohs hardness 7, no cleavage, conchoidal fracture, and hexagonal crystal structure. The specimen appears small and possibly naturally terminated, though the image is not detailed enough to confirm.

Identified August 28, 2026More mineral →

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Physical properties

Formation & geological history

Smoky quartz forms in cavities and fractures of granitic pegmatites and hydrothermal veins when natural irradiation creates color centers; crystals range from Precambrian to recent in age. Common sources include Brazil, Switzerland, the United States, Madagascar, and Scotland.

Uses & applications

Used as a collector mineral and occasionally as a gemstone; larger clear crystals may be faceted or polished. Small specimens typically have modest commercial value.

Geological facts

The brown color can fade with strong heat or sunlight, and some dark smoky quartz is artificially irradiated. Quartz commonly forms six-sided prisms ending in pyramidal faces.

Field identification & locations

Check for glassy luster, hardness sufficient to scratch ordinary glass, lack of cleavage, and a hexagonal prism or conchoidal fracture. Dark inclusions or irregular shape could instead indicate tourmaline, garnet, or another brown mineral.