mineral

Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Colorless to white/cloudy
Luster: Vitreous (glassy)

Identified June 14, 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 to white/cloudy; Luster: Vitreous (glassy); Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Forms in a wide variety of environments, most commonly from the cooling of magma (igneous) or through hydrothermal activity in veins. It is one of the most abundant minerals in the Earth's crust and can be found in rocks from almost every geological age.

Uses & applications

Used extensively in glass making, electronics (piezoelectric properties), abrasives, construction as an aggregate, and in jewelry and gemstone collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It was historically believed by some cultures to be 'permanent ice' frozen by the gods. It defines the '7' mark on the Mohs hardness scale.

Field identification & locations

Identify in the field by its hardness (cannot be scratched by a steel knife) and its glass-like appearance with irregular, curved fracture surfaces rather than flat cleavage planes. Check for its ability to scratch glass.