mineral

Quartz Vein Outcrop

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: White/milky to clear, Luster: Vitreous/glassy, Crystal structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified April 20, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: White/milky to clear, Luster: Vitreous/glassy, Crystal structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed through hydrothermal processes where silica-rich fluids are injected into fractures in surrounding country rock and crystallize as they cool. These veins can range from Precambrian to Cenozoic in age.

Uses & applications

Used as a source of high-purity silica for the electronics industry, glass manufacturing, and as decorative stone or landscaping material. Large crystals are prized by collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its white color from tiny pocket inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its superior hardness (cannot be scratched by a steel knife), white/milky color against darker soil, and lack of cleavage. Often found near hydrothermal gold deposits.