mineral
Smoky quartz crystal
Quartz (SiO₂), likely smoky variety
AI-generated identification · may be incorrectTranslucent gray-brown with vitreous luster and irregular crystal faces; Mohs hardness 7, trigonal crystal system, no cleavage, conchoidal fracture. The photo alone cannot confirm the variety; similar-looking minerals are possible.
Identified More mineral →
Explore Smoky quartz crystal in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Translucent gray-brown with vitreous luster and irregular crystal faces; Mohs hardness 7, trigonal crystal system, no cleavage, conchoidal fracture. The photo alone cannot confirm the variety; similar-looking minerals are possible.
Formation & geological history
Quartz commonly crystallizes from silica-rich fluids in cavities and pegmatites, over a wide range of geological ages. Smoky coloration usually results from irradiation acting on trace aluminum impurities.
Uses & applications
Used for jewelry, carving, and mineral collecting; quartz is also important in glassmaking and electronics.
Geological facts
Quartz is one of Earth’s most abundant minerals; smoky color can range from pale gray to nearly black.
Field identification & locations
Check for hardness near 7, glassy luster, and conchoidal fracture; common sources include Brazil, Madagascar, the Alps, and the United States. Avoid scratch-testing a valued specimen.
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
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
Septarian Pebble
Septarian nodule / Concretion
sedimentary