mineral

Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Translucent to milky white with some iron staining (orange/brown). Luster: Vitreous (glassy). Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Luster: Vitreous (glassy)

Identified July 11, 2026More mineral →

Explore Quartz in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Forms in a wide variety of environments, most commonly by hydrothermal precipitation from hot silica-rich solutions in veins or as a late-stage crystallization in igneous rocks like granite. It is found in deposits ranging from the Precambrian to modern times.

Uses & applications

Used extensively in glass making, as an abrasive, in electronics (due to piezoelectric properties), and as a gemstone or decorative mineral for collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is extremely resistant to weathering, which is why it is the primary component of most beach sands.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), its lack of cleavage, and its characteristic glassy luster. It is found globally in almost every geological setting.