mineral

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale (it can scratch glass). Color: Clear/Colorless. Luster: Vitreous (glassy). Crystal Structure: Hexagonal/Trigonal (specifically forming six-sided prisms). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale (it can scratch glass)
Color: Clear/Colorless
Luster: Vitreous (glassy)

Identified February 18, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the crystallization of magma or from hydrothermal veins. It is found in all types of geological environments and can be found in rocks dating back to the Archean Eon. Many clear specimens form in cavity-rich igneous environments like pegmatites.

Uses & applications

Used widely in electronics for its piezoelectric properties. In crystal healing, jewelry (as semi-precious gemstones), watchmaking, and as an abrasive in glass making and manufacturing.

Geological facts

Quartz is the second most abundant mineral in the Earth's continental crust. Historically, the Greeks believed crystal quartz was actually water frozen into permanent ice. Today, 'quartz' crystals found in wristwatches keep time by vibrating at a precise frequency when an electric current is applied.

Field identification & locations

Identify in the field by its hardness (will not be scratched by a steel knife), its lack of cleavage (it breaks into curved, shell-like glass shards), and its six-sided crystal faces. Common locations include Brazil, Madagascar, and the United States (specifically Arkansas and New York).

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