mineral

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

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

Hardness: 7 on Mohs scale
Color: Colorless/Transparent
Luster: Vitreous (glassy)

Identified March 8, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments through the cooling of silica-rich magma or precipitation from hydrothermal veins. It is found in geological formations ranging from the Archean Eon to recent times.

Uses & applications

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

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. 'Rock Crystal' comes from the Greek word 'krystallos', meaning ice, as ancient Greeks believed it was ice that had frozen so hard it would never melt.

Field identification & locations

Identify in the field by its hardness (scratches glass), lack of cleavage, and vertical striations on crystal faces. Found globally, with notable deposits in Brazil, Madagascar, and Arkansas, USA.

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