mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milk-white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milk-white to opaque
Luster: Vitreous to greasy

Identified June 27, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milk-white to 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. Milky quartz specifically gets its appearance from tiny fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, abrasives, foundry sand, and as a gemstone. It is also used in the manufacturing of oscillators for watches and electronics due to its piezoelectric properties.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is often the variety found in gold-bearing hydrothermal veins, making it a target for prospectors.

Field identification & locations

Identify by its ability to scratch glass, its lack of cleavage, and its waxy or vitreous luster. It is found globally in almost all geological environments.