mineral

Tumbled smoky quartz

Quartz (SiO₂), brown smoky variety

AI-generated identification · may be incorrect

Mohs hardness 7; transparent to translucent brown-gray color, vitreous luster, and no visible cleavage. It has a hexagonal crystal structure, though tumbling has rounded the pieces and obscured crystal faces; specific gravity is about 2.65.

Identified August 23, 2026More mineral →

Explore Tumbled smoky quartz in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Smoky quartz forms when natural or irradiation-induced color centers develop in quartz, commonly in granitic pegmatites, hydrothermal veins, and cavities. The pictured material appears tumbled and polished rather than naturally weathered.

Uses & applications

Used for ornamental objects, cabochons, beads, and inexpensive jewelry; attractive transparent pieces are popular among mineral collectors.

Geological facts

The smoky color can result from aluminum impurities activated by natural radiation. It may fade with prolonged strong heat or sunlight, while very dark material may be heat-treated amethyst or colorless quartz.

Field identification & locations

Identify it by glassy luster, rounded conchoidal fractures, hardness sufficient to scratch ordinary glass, and lack of cleavage; quartz should not be confused with softer brown glass or resin. Common localities include Brazil, Switzerland, Madagascar, Scotland, and the United States.