mineral

Quartz

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale. Color varies widely from colorless/white to smoky, pink, purple, etc. Vitreous to greasy luster. Trigonal crystal system. Conchoidal fracture with no true cleavage. Specific gravity is 2.65.

Identified July 28, 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 geological environments, most commonly in igneous, metamorphic, and sedimentary rocks. It is a major constituent of granite and sandstone and precipitates from hydrothermal solutions.

Uses & applications

Used in electronics (oscillators), glassmaking, abrasive materials, gemstone carving, and ornamental displays.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust, surpassed only by feldspar. It exhibits piezoelectric properties, generating an electric charge under mechanical stress.

Field identification & locations

Easily identified by its characteristic high hardness (scratches glass), conchoidal fracture, and lack of cleavage. Found worldwide in nearly every geological setting.