mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

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

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

Identified May 30, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the crystallization of magma or from hydrothermal veins. It can be found in a wide variety of igneous, metamorphic, and sedimentary environments globally, spanning all geological eras.

Uses & applications

Used in electronics (oscillators), glassmaking, abrasives, jewelry (gemstones), and healing crystal collections.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is known as rock crystal; and it was historically believed to be permanently frozen ice by ancient Greeks.

Field identification & locations

Identify by its ability to scratch glass, its hexagonal crystal habit (if preserved), and its lack of cleavage. Found in riverbeds, mountains, and mines worldwide; notably in Brazil, Arkansas (USA), and the Alps.