mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

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

Hardness: 7 (Mohs scale)
Color: White to opaque (milky)
Luster: Vitreous to greasy

Identified June 21, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to opaque (milky); 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 precipitation in veins. Milky quartz particularly occurs when microscopic fluid inclusions of gas or liquid are trapped during crystal growth.

Uses & applications

Used as a major component in glass making, ceramics, and as an abrasive. In smaller, aesthetic forms, it is used for decorative landscaping, lapidary work, and crystal collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The 'milky' appearance is caused by millions of tiny bubbles of gas and liquid trapped within the crystal structure.

Field identification & locations

Identify in the field by its hardness (cannot be scratched by steel) and lack of cleavage (breaks like glass). It is found globally in almost all geological environments, especially in hydrothermal veins.