mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glass-like); Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

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

Identified April 4, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glass-like); Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed through the crystallization of molten magma or through hydrothermal activity in pegmatites and veins. It is found in all types of geological environments and can be millions to billions of years old.

Uses & applications

Used widely in electronics (oscillators), optics, glassmaking, abrasive industries, and as a semi-precious gemstone in jewelry and carving.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is traditionally called rock crystal or clear quartz and was once believed by ancient Greeks to be permanently frozen ice.

Field identification & locations

Identify by its ability to scratch glass, its colorless transparency, and lack of cleavage. It is found globally, with major deposits in Brazil and Arkansas, USA.