mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Colorless and transparent; Luster: Vitreous (glass-like); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Colorless and transparent
Luster: Vitreous (glass-like)

Identified March 10, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale; Color: Colorless and 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 magma or via hydrothermal activity in veins. It is found in igneous, metamorphic, and sedimentary environments across all geological ages.

Uses & applications

Used in electronics (oscillators), high-precision glass, jewelry (faceting and cabochons), and highly valued in various metaphysical and collector circles.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure clear specimens are often referred to as 'Rock Crystal' and were once believed by ancient Greeks to be ice that had frozen so hard it would never melt.

Field identification & locations

Identify in the field by its transparency, ability to scratch glass (Hardness 7), and lack of cleavage planes. Found globally, notably in Brazil, Arkansas (USA), and Madagascar.