mineral

Quartz

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale, color is typically white, milky, or clear with brownish iron oxide staining visible on the top surface, vitreous to greasy luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Identified August 2, 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 precipitating from silica-rich hydrothermal solutions or crystallizing from cooling magma in pegmatites and granites, as well as accumulating in sedimentary environments as weathered quartz sandstones.

Uses & applications

Used in electronics, glassmaking, abrasives, gemstone carvings, and as a popular mineral specimen for rock collectors.

Geological facts

Quartz is one of the most abundant and widely distributed minerals found on Earth's continental crust. Its piezoelectric properties make it essential for timing and frequency control in electronic devices like watches.

Field identification & locations

Easily identified in the field by its high hardness (it easily scratches glass and steel), lack of cleavage, and characteristic conchoidal fracture. Found worldwide in almost every rock type.