mineral

Clear Quartz

Silicon Dioxide (SiO2) / Rock Crystal

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

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

Identified March 28, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling and crystallization of silica-rich hydrothermal solutions or magma. It can be found in a wide variety of igneous, metamorphic, and sedimentary environments across all geological ages.

Uses & applications

Extensively used in jewelry as a gemstone, in glass manufacturing, as an abrasive, and in the electronics industry for its piezoelectric properties (oscillators for clocks and radios). It is also a popular specimen for crystal collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Historically, the word 'crystal' is derived from the Greek word 'krustallos', meaning ice, as ancient Greeks believed quartz was ice that had frozen so hard it would never melt.

Field identification & locations

Identify in the field by its hardness (will scratch glass), hexagonal crystal habit (six-sided prisms), and lack of cleavage. It is found globally, with major deposits in Brazil, Madagascar, and the United States (Arkansas). Collectors look for clarity and well-defined terminations.