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), Specific Gravity: 2.65

Identified June 30, 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), Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or through hydrothermal activity in veins. It is found in a wide variety of igneous, metamorphic, and sedimentary environments throughout all geological ages.

Uses & applications

Used in glassmaking, abrasives, foundry sand, and as a raw material in the electronics industry. Low-grade specimens like this are common in landscaping and construction aggregate.

Geological facts

Quartz is the most abundant and widely distributed mineral found at Earth's surface. Milky quartz gets its cloudiness from tiny fluid inclusions of gas and/or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and white opaque appearance. It is exceptionally common in gravel pits, stream beds, and mountainous regions worldwide.