mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless to transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Colorless to transparent
Luster: Vitreous (glassy)

Identified April 12, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of magma or by hydrothermal activity in veins. It is found in a wide variety of igneous, metamorphic, and sedimentary environments across all geological ages.

Uses & applications

Used in electronics (oscillators), optics, glassmaking, abrasives, and as a semi-precious gemstone in jewelry and metaphysical collections.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz, like this specimen, is traditionally called 'Rock Crystal' and was once believed by ancients to be permanently frozen ice.

Field identification & locations

Identify in the field by its hardness (it scratches glass), its glassy luster, and its characteristic conchoidal (shell-like) fracture patterns. It is found globally, notably in Brazil, Arkansas (USA), and the Alps.