mineral

Smoky quartz crystal

Quartz (silicon dioxide, SiO₂), smoky variety

AI-generated identification · may be incorrect

Translucent gray-brown to smoky brown with a vitreous luster and irregular crystal surfaces. Mohs hardness 7; trigonal crystal structure, no cleavage, and conchoidal fracture; specific gravity about 2.65.

Identified October 10, 2026More mineral →

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Physical properties

Formation & geological history

Forms as silica-rich fluids crystallize in fractures, pegmatites, and hydrothermal veins; its smoky color commonly results from natural irradiation acting on trace aluminum. The specimen’s exact age and locality cannot be determined from the image.

Uses & applications

Used in jewelry, carvings, and mineral collections; quartz is also important in glassmaking and electronics.

Geological facts

Smoky quartz gets its color from radiation-induced defects in the crystal lattice, rather than from smoke or organic staining.

Field identification & locations

Look for glassy luster, hardness sufficient to scratch ordinary glass, and lack of cleavage; common sources include Brazil, the Alps, and parts of the United States. The pictured rough brown-gray material is consistent with quartz, though identification from an image is not definitive.