mineral

Quartz

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale, clear to milky white color, vitreous luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Identified July 31, 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, clear to milky white color, vitreous luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Formation & geological history

Forms in a wide variety of geological environments, most commonly crystallized from silica-rich hydrothermal veins and magma in igneous rocks like granite, as well as precipitating in sedimentary environments.

Uses & applications

Used in electronics, oscillators, glassmaking, abrasives, gemstones, and ornamental carvings.

Geological facts

Quartz is one of the most abundant minerals in Earth's continental crust and exhibits piezoelectric properties, meaning it can generate an electrical charge when mechanically stressed.

Field identification & locations

Easily identifiable by its high hardness (scratches glass easily), lack of cleavage, and vitreous luster. Found globally across almost every continent.