mineral

Quartz (Milky/Clear Quartz)

Silicon Dioxide (SiO2)

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

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

Identified July 12, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in a wide variety of environments, primarily through the cooling of silica-rich magma or from hydrothermal veins. It is found in igneous, metamorphic, and sedimentary rocks across all geological ages.

Uses & applications

Extensively used in glassmaking, electronics (piezoelectric properties), abrasives, construction, and as a popular semi-precious gemstone in jewelry and crystal collecting.

Geological facts

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

Field identification & locations

Identify in the field by its hardness (will scratch glass and steel), lack of cleavage, and glassy appearance. It is found globally, with significant deposits in Brazil, the USA (Arkansas), and the Alps.