mineral
Clear quartz (rock crystal)
Quartz, silicon dioxide (SiO₂)
AI-generated identification · may be incorrectColorless to translucent with a vitreous luster and irregular, glassy fracture; Mohs hardness 7, trigonal crystal structure, no cleavage, specific gravity about 2.65. The pictured piece appears rough and naturally fractured.
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Physical properties
Colorless to translucent with a vitreous luster and irregular, glassy fracture; Mohs hardness 7, trigonal crystal structure, no cleavage, specific gravity about 2.65. The pictured piece appears rough and naturally fractured.
Formation & geological history
Forms when silica-rich fluids crystallize in cavities and veins, or during cooling of silica-rich magma; quartz occurs in rocks of many geological ages.
Uses & applications
Used in jewelry and ornamental objects; industrial quartz is important in glassmaking, abrasives, and electronics.
Geological facts
Quartz is one of Earth’s most abundant minerals and is piezoelectric, producing an electrical charge under pressure.
Field identification & locations
Look for glassy luster, hardness sufficient to scratch ordinary glass, and absence of cleavage; common worldwide in veins, pegmatites, and many rock types. The photo alone cannot establish locality or geological age.
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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
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Granite
Granite (Phaneritic intrusive igneous rock)
igneous