mineral

Polished smoky quartz with iron-stained quartz inclusion

Smoky quartz, SiO₂; inclusion likely quartz with iron-oxide staining

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent brown to smoky gray, vitreous luster, conchoidal fracture, no cleavage, hexagonal quartz structure; specific gravity about 2.65. The specimen appears naturally fractured and partly polished or water-worn, with a contrasting pale quartz inclusion.

Identified August 28, 2026More mineral →

Explore Polished smoky quartz with iron-stained quartz inclusion 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 in silica-rich hydrothermal veins, pegmatites, and granitic cavities when natural radiation colors quartz centers brown. Quartz inclusions and iron oxides formed during later fluid movement; age varies from millions to billions of years.

Uses & applications

Used as an ornamental and lapidary stone, carving material, and inexpensive jewelry or crystal specimen; not generally used as aggregate because of specimen quality.

Geological facts

Its smoky color commonly results from aluminum impurities activated by irradiation. Color may fade with prolonged heating or intense sunlight.

Field identification & locations

Identify by glassy luster, conchoidal fracture, hardness sufficient to scratch ordinary glass, and lack of cleavage; common localities include Brazil, Madagascar, Switzerland, the United States, and worldwide granitic terrains.