mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Colorless/Transparent
Luster: Vitreous (glassy)

Identified May 25, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct; Specific Gravity: 2.65

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments. Typically crystallizes from cooling magma or hydrothermal veins. It is found in many geological ages from Precambrian to recent.

Uses & applications

Used in electronics for its piezoelectric properties, glass manufacturing, jewelry, and as decorative tumbled stones for collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Historically, the Greeks believed clear quartz was ice that had frozen so hard it could never melt.

Field identification & locations

Identify by its hardness (scratches glass), lack of cleavage, and transparent appearance. Commonly found in mountain ranges, riverbeds, and as geodes in volcanic areas.