mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

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

Identified June 1, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: White to milky 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 from hydrothermal veins. It is found in a wide variety of geological environments including igneous, metamorphic, and sedimentary rocks throughout all geological ages.

Uses & applications

Used in glassmaking, abrasives, electronics (piezoelectric properties), and as a base material for construction aggregates. Lower quality milky quartz is primarily used in landscaping or as a source of silicon.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The white 'milky' appearance is caused by tiny fluid inclusions of gas and/or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass) and its lack of cleavage. It is ubiquitous globally, especially in mountain ranges and riverbeds. Collectors look for well-defined hexagonal crystal points.