mineral
Smoky quartz (polished cabochon or crystal piece)
Quartz, SiO₂; smoky variety
AI-generated identification · may be incorrectTranslucent smoky-brown material with vitreous luster; Mohs hardness 7, trigonal crystal structure, no cleavage and conchoidal fracture. The image is too close and reflective to confirm the specimen’s exact cut or clarity.
Identified More mineral →
Explore Smoky quartz (polished cabochon or crystal piece) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Translucent smoky-brown material with vitreous luster; Mohs hardness 7, trigonal crystal structure, no cleavage and conchoidal fracture. The image is too close and reflective to confirm the specimen’s exact cut or clarity.
Formation & geological history
Forms in silica-rich pegmatites and hydrothermal veins; its brown color is typically caused by natural irradiation of trace aluminum in quartz. Quartz occurs in rocks of many geological ages.
Uses & applications
Used for jewelry, carvings, and mineral collecting; quartz also has broad industrial use in glass and electronics.
Geological facts
Smoky quartz is common and durable, and its color may range from pale gray-brown to nearly black.
Field identification & locations
Identify by hardness, glassy luster, lack of cleavage, and (in crystal form) six-sided prisms; common sources include Brazil, the Alps, and the United States. The image alone does not establish locality or whether the color is natural.
More like this
Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous