mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

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

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

Identified April 8, 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; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. It can be found in virtually all geological environments across all ages, though large crystals often form in pegmatites.

Uses & applications

Extensively used in jewelry, decorative items, and 'healing' crystals. Industrially used in electronics (oscillators), glass making, and precision optical instruments.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Rock crystal was once believed by the Greeks to be eternal ice that had frozen so hard it would never melt.

Field identification & locations

Identify in the field by its extreme clarity, hexagonal shape (if crystal), and ability to scratch glass. Found globally, especially in Brazil, Madagascar, and Arkansas (USA). For collectors, look for lack of bubbles (which would indicate glass).