mineral

Tumbled smoky quartz (probable)

Quartz, silicon dioxide (SiO₂), likely smoky variety with iron- or radiation-related coloration

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent gray-brown to smoky black, with vitreous luster and conchoidal fracture. Quartz is trigonal and lacks cleavage; the rounded surface indicates tumbling/polishing, and dark inclusions or matrix may be present.

Identified September 13, 2026More mineral →

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Physical properties

Formation & geological history

Forms in silica-rich hydrothermal veins, cavities, and granitic pegmatites; coloration develops through natural irradiation of aluminum-bearing quartz. Individual crystals may range from ancient Precambrian to geologically recent deposits.

Uses & applications

Used as an ornamental and lapidary stone, in jewelry, carvings, and mineral collections; quartz also has major industrial uses in glass, electronics, and abrasives.

Geological facts

Smoky quartz can become nearly black (“morion”) and may fade with prolonged heating or intense light. The image is not sufficient to distinguish it confidently from dark agate, tourmalinated quartz, or another quartz-rich tumbled stone.

Field identification & locations

Commonly found in Brazil, Madagascar, Switzerland, the United States, and Scotland. Check for glassy luster, conchoidal fracture, hardness near 7, and absence of bubbles; a scratch test or refractive-index test can confirm quartz.