Clear Quartz (Rock Crystal)

Physical Properties

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & Geological History

Formed through the cooling of silica-rich magma or from hydrothermal veins. It is found in all types of geological environments and can be millions to billions of years old.

Uses & Applications

Used in jewelry, meditation/healing practices, precision electronics (piezoelectric properties), and glassmaking.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Rock crystal was once believed by Ancient Greeks to be permanently frozen ice.

Field Identification & Locations

Identify by its ability to scratch glass and its lack of cleavage (breaking in curved, shell-like patterns). Found globally, with notable deposits in Brazil and Arkansas, USA.

Identified on: 4/25/2026

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