mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7
Color: White to translucent milky gray
Luster: Vitreous to greasy

Identified June 27, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in hydrothermal veins, pegmatites, and as a primary constituent in igneous rocks like granite. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), construction aggregates, and low-cost jewelry or landscaping.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It can sometimes contain small amounts of gold in hydrothermal vein systems.

Field identification & locations

Identify by its ability to scratch glass, its lack of cleavage, and its waxy/greasy luster on broken surfaces. It is ubiquitous globally especially in mountain ranges and gravel pits.