mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glass-like); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Colorless/Transparent
Luster: Vitreous (glass-like)

Identified March 15, 2026More mineral →

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: Colorless/Transparent; Luster: Vitreous (glass-like); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments. Typically crystallizes from silica-rich hydrothermal veins or cooling magma (pegmatites). It can be found in rocks from the Precambrian to recent ages.

Uses & applications

Used in electronics for its piezoelectric properties (watches, radios), high-end glass manufacturing, gemstones for jewelry, and as decorative or metaphysical display pieces.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. When absolutely pure, it is perfectly clear; the 'Herkimer Diamond' is a famous variety of double-terminated quartz from New York.

Field identification & locations

Identify in the field by its hardness (will scratch glass and steel), lack of cleavage, and six-sided hexagonal prisms with pyramid-like terminations. Common locations include Brazil, Madagascar, and Arkansas, USA.