mineral

Likely smoky quartz

Quartz, SiO₂ (smoky variety)

AI-generated identification · may be incorrect

Translucent to dark brown with a glassy luster and irregular, curved fracture surfaces; Mohs hardness 7, trigonal crystal structure, and no cleavage. The photo suggests a rough quartz fragment, though identification is not certain from appearance alone.

Identified October 4, 2026More mineral →

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Physical properties

Formation & geological history

Smoky quartz crystallizes from silica-rich fluids in cavities and veins, commonly in granites and pegmatites. Its brown color typically results from natural irradiation of trace aluminum; crystals may form over long geological periods.

Uses & applications

Used for jewelry, carvings, and mineral collecting; quartz also has broad industrial uses, though this fragment appears suited mainly to collecting.

Geological facts

Quartz is abundant worldwide, and smoky coloration can develop naturally in otherwise clear quartz.

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 piece may also be another dark, fractured mineral, so a hardness test or closer examination would help.