mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale), Color: White to yellowish-tan, Luster: Vitreous to waxy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified June 30, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: White to yellowish-tan, Luster: Vitreous to waxy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or pegmatites from silica-rich solutions settling in rock fractures. Its cloudy appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, construction aggregates, jewelry, as a source for silicon metal, and in electronics for its piezoelectric properties.

Geological facts

Quartz is the second most abundant mineral in Earth's crust. Its name comes from the German word 'quarz', which originally meant 'hard'. The milky appearance is due to millions of fluid inclusions.

Field identification & locations

The provided coordinates near Sao Paulo, Brazil, are within the crystalline basement of the Mantiqueira Province, where quartz-rich pegmatites and metamorphic rocks are extremely common. Identify by its ability to scratch glass and lack of cleavage.