mineral

Smoky quartz crystal

Quartz (silicon dioxide, SiO₂), likely smoky quartz

AI-generated identification · may be incorrect

Typically Mohs hardness 7, vitreous luster, conchoidal fracture, and hexagonal crystal structure; the image shows a small translucent brown-to-gray crystal with apparent prism faces. Exact identification is limited by the close, dim photograph.

Identified August 17, 2026More mineral →

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Physical properties

Formation & geological history

Smoky quartz forms in silica-rich hydrothermal veins, pegmatites, and cavities in igneous rocks when natural radiation colors clear quartz; crystals range from ancient to geologically recent. Common localities include Brazil, Madagascar, Switzerland, the United States, and Scotland.

Uses & applications

Used as a collectible mineral and occasional gemstone; quartz is also important industrially for glass, electronics, abrasives, and engineered stone.

Geological facts

The smoky color results from irradiation affecting aluminum-related defects in the quartz lattice, and it can fade with prolonged heating or intense light.

Field identification & locations

Look for glassy luster, hardness sufficient to scratch ordinary glass, no cleavage, and six-sided prismatic geometry; confirm with a scratch test and magnification. The specimen may also be dark fluorite or coated glass if it fails these tests.