mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous; Crystal Structure: Hexagonal (Trigonal); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65.

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

Identified July 21, 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; Crystal Structure: Hexagonal (Trigonal); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed through the cooling and crystallization of silica-rich magma or from hydrothermal veins. It can be found in igneous, metamorphic, and sedimentary environments globally, often spanning millions of years in age.

Uses & applications

Used in electronics (oscillators), glassmaking, abrasives, jewelry (facet and beads), and as a popular specimen for gemstone collectors and metaphysical practices.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is known as rock crystal; when it contains impurities, it creates varieties like amethyst (purple) or citrine (yellow).

Field identification & locations

Identify by its ability to scratch glass (hardness) and the presence of conchoidal (shell-like) fracture patterns without cleavage planes. Look for hexagonal prism shapes in raw crystals.