mineral

Tumbled smoky quartz

Quartz, silicon dioxide (SiO₂), smoky variety

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent gray-brown to smoky black, with a vitreous luster and conchoidal fracture. Trigonal crystal structure; the rounded shape is from tumbling, not natural crystallization.

Identified August 30, 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

Hardness 7 Mohs; translucent gray-brown to smoky black, with a vitreous luster and conchoidal fracture. Trigonal crystal structure; the rounded shape is from tumbling, not natural crystallization.

Formation & geological history

Forms in silica-rich hydrothermal veins, pegmatites, and cavities in igneous rocks; its smoky color results from irradiation affecting aluminum impurities. Specimen age depends on its host deposit, commonly millions to hundreds of millions of years.

Uses & applications

Used as an ornamental and lapidary stone, in cabochons and carvings, and occasionally as a collectible mineral; quartz also has major industrial uses in glass and electronics.

Geological facts

Smoky quartz is commonly mistaken for brown glass or darker varieties such as morion. Natural material usually shows internal veils, fractures, or uneven color rather than perfectly uniform transparency.

Field identification & locations

Common localities include Brazil, Switzerland, Madagascar, the United States, and Spain; identify it by its glassy luster, hardness, cool feel, and inability to be scratched by steel. The image appears to show a polished/tumbled piece with internal fracture or mineral inclusions.