mineral

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Colorless/Transparent
Luster: Vitreous (glassy)

Identified July 12, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments. It crystallizes from cooling magma or precipitates from hydrothermal veins. It is found in earth's crust across all geological ages.

Uses & applications

Used in electronics for its piezoelectric properties, glass manufacturing, abrasives, timekeeping (watches), and extensively in jewelry and gemstone collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure colorless quartz is known as 'rock crystal' and was once believed by ancient Greeks to be ice that had frozen so hard it would never melt.

Field identification & locations

Identified by its ability to scratch glass, its lack of cleavage (it breaks in curved, shell-like fractures), and its typical six-sided crystal habit. Found globally in mountains, riverbeds, and beaches.