mineral

Quartz (Common or Milky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless to white/light grey; Luster: Vitreous (glassy); Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Colorless to white/light grey
Luster: Vitreous (glassy)

Identified June 25, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Colorless to white/light grey; Luster: Vitreous (glassy); Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Found in all types of geological environments; primarily forms from cooling magma in igneous rocks like granite or crystallizes from hydrothermal veins. It is highly resistant to weathering and is billions of years old in many crustal occurrences.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, watches, and as a semi-precious gemstone in jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is the main component of most beach sands and can generate an electric charge when mechanical pressure is applied.

Field identification & locations

Identify by its inability to be scratched by a steel knife and its glass-like appearance without cleavage planes. Found globally in mountains, rivers, and quarries. Use a scratch test and look for conchoidal (curved) fracture surfaces.

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Mineral/Rock

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mineral