mineral

Quartz (Common or Milky)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to tan/milky; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to tan/milky
Luster: Vitreous to greasy

Identified June 25, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to tan/milky; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma/hydrothermal fluids or as a sedimentary deposit. It is one of the most abundant minerals in the Earth's crust, occurring in nearly all geological ages.

Uses & applications

Used extensively in the electronics industry (piezoelectric properties), glassmaking, abrasives, construction as an aggregate, and occasionally as a semi-precious gemstone in jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is chemically stable and physically resistant, which is why it is the primary component of beach sand.

Field identification & locations

Identify by its hardness (it can scratch glass), lack of cleavage, and translucent appearance. It is commonly found in riverbeds, mountains, and desert surfaces.