mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: White/Opaque, Luster: Vitreous to greasy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), SG: 2.65

Identified May 24, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: White/Opaque, Luster: Vitreous to greasy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), SG: 2.65

Formation & geological history

Formed in hydrothermal veins and pegmatites through the cooling of silica-rich magma or precipitation from hot aqueous solutions. It is found in rocks of all geological ages.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, construction as aggregate, and frequently collected as a semi-precious gemstone or decorative specimen.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its characteristic white opacity from tiny fluid inclusions trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and white sugary or glassy appearance. It is ubiquitous globally in mountains, riverbeds, and beaches.