mineral

Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to translucent milky white; Luster: Vitreous/glassy; Crystal System: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Clear to translucent milky white
Luster: Vitreous/glassy

Identified July 22, 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

Hardness: 7 on Mohs scale; Color: Clear to translucent milky white; Luster: Vitreous/glassy; Crystal System: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in a wide range of geological environments, most commonly in pegmatites, hydrothermal veins, and igneous rocks through crystallization from silicate fluids. Found globally in all age formations.

Uses & applications

Used extensively in electronics (piezoelectric crystals), glassmaking, abrasives, gemstones, construction materials, and as quartz aggregate in countertops.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It exhibits piezoelectricity, meaning it generates an electrical charge when subjected to mechanical stress.

Field identification & locations

Identified by its ability to scratch glass (hardness 7), lack of cleavage, vitreous luster, and translucent to clear appearance. Commonly found worldwide in mountain ranges, stream beds, and pegmatite deposits.