
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, brownish-grey to almost black color, vitreous luster, trigonal crystal system, conchoidal fracture, specific gravity of 2.65
Identified More mineral →
Explore Smoky Quartz in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 7 on the Mohs scale, brownish-grey to almost black color, vitreous luster, trigonal crystal system, conchoidal fracture, specific gravity of 2.65
Formation & geological history
Formed from hydrothermal solutions or igneous and metamorphic rocks where natural irradiation of silicon dioxide containing trace aluminum impurities creates the brown color
Uses & applications
Used in jewelry, ornamental carvings, lapidary arts, and spiritual or metaphysical practices
Geological facts
The color in smoky quartz is caused by free silicon formed from silicon dioxide by natural radioactive sources in the surrounding rock
Field identification & locations
Identified by its characteristic brown-to-grey translucent appearance and hardness that scratches glass easily; commonly found in pegmatites worldwide