mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Hardness: 7.0 Mohs; Color: White to off-white, translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7
Color: White to off-white, translucent
Luster: Vitreous to greasy

Identified June 1, 2026More mineral →

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Physical properties

Hardness: 7.0 Mohs; Color: White to off-white, translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in a variety of environments, most commonly from the cooling of magma (igneous) or precipitation from hydrothermal veins. It is found in all geological ages.

Uses & applications

Used in glass manufacturing, electronics (piezoelectric 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 chemically and physically resistant to weathering, which is why it often remains as sand on beaches.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. It is found globally in many environments including mountains, riverbeds, and deserts. Look for the characteristic glassy luster on broken surfaces.