mineral

Quartz (Common or Milky)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless to white/translucent with yellowish iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Colorless to white/translucent with yellowish iron staining
Luster: Vitreous to greasy

Identified July 18, 2026More mineral →

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Physical properties

Formation & geological history

Forms through the cooling of silica-rich magma or from hydrothermal veins. It is one of the most abundant minerals in the Earth's crust and can be found in igneous, metamorphic, and sedimentary environments.

Uses & applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, jewelry (semiprecious), and as a component in construction materials like concrete.

Geological facts

Quartz is chemically and physically very resistant to weathering. It is the primary constituent of most white beach sand and is found on every continent.

Field identification & locations

Identify by its hardness (it will scratch glass), its lack of cleavage, and its characteristic greasy luster on fractured surfaces. Often found as rounded pebbles in riverbeds or as veins in bedrock.