mineral

Quartz (Common or Milky)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs), Color: Colorless to white/yellowish, Luster: Vitreous to greasy, Crystal structure: Trigonal (hexagonal prisms), Cleavage: None (conchoidal fracture), Specific gravity: 2.65

Identified April 3, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs), Color: Colorless to white/yellowish, Luster: Vitreous to greasy, Crystal structure: Trigonal (hexagonal prisms), Cleavage: None (conchoidal fracture), Specific gravity: 2.65

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments. It crystallizes from magma or precipitates from hydrothermal veins. It is found in nearly all geological ages and environments globally.

Uses & applications

Used extensively in glass manufacturing, electronics (pigzoelectric properties), abrasives, gemstones, and as a component in concrete and mortar.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is extremely resistant to weathering, which is why it is the primary component of most beach sand.

Field identification & locations

Identify by its 7 hardness (it can scratch glass), lack of cleavage, and glassy appearance. Found virtually everywhere, including riverbeds, mountains, and beaches. Look for its characteristic hexagonal crystal faces in well-formed specimens.