mineral

Quartz

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness of 7 on the Mohs scale, transparent to translucent with a vitreous (glassy) luster, hexagonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Identified August 6, 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 of 7 on the Mohs scale, transparent to translucent with a vitreous (glassy) luster, hexagonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Formation & geological history

Forms in a wide variety of geological environments including igneous, metamorphic, and sedimentary rocks. Often precipitates from silica-rich hydrothermal solutions or crystallizes directly from cooling magma.

Uses & applications

Used extensively in glassmaking, electronics, oscillators, abrasives, gemstones, and construction materials.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust, surpassed only by feldspar. Its piezoelectric properties make it essential for keeping time in watches.

Field identification & locations

Easily identified in the field by its distinctive crystal shape, high hardness (scratches glass easily), and lack of cleavage. Found worldwide in nearly every geological setting.