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 June 28, 2026More mineral →

Explore Clear Quartz (Rock Crystal) in the encyclopedia →

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

Formed from cooling silica-rich magma or hydrothermal veins; can be found in igneous, metamorphic, and sedimentary environments globally.

Uses & applications

Used in electronics (oscillators), optics, glassmaking, jewelry (as a gemstone), and metaphysical practices.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is piezoelectric, meaning it generates an electric charge when mechanical stress is applied.

Field identification & locations

Identify by its hardness (scratches glass), glass-like appearance, and lack of cleavage. Commonly found in riverbeds, mountains, and mines in countries like Brazil and the USA.