Clear Quartz (Rock Crystal)

Physical Properties

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

Formation & Geological History

Formed from silica-rich hydrothermal solutions or the cooling of magma. It can be found in igneous, metamorphic, and sedimentary rocks across all geological ages, often in veins or geodes.

Uses & Applications

Used in electronics (oscillators), glassmaking, abrasives, jewelry, and as a popular metaphysical or decorative collector's stone.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. It is piezoelectric, meaning it generates an electric charge when mechanical stress is applied.

Field Identification & Locations

Identify in the field by its transparency, its ability to scratch glass (hardness 7), and its lack of cleavage (it breaks in curved, shell-like fractures). Found globally, with significant deposits in Brazil, Arkansas, and Madagascar.

Identified on: 4/16/2026

Mode: Standard