mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Cloudy white to grayish; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Cloudy white to grayish
Luster: Vitreous to greasy

Identified July 10, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Cloudy white to grayish; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

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

Uses & applications

Used in glass making, abrasive materials, gravel for road construction, and as a source of silicon for electronics. While low-value, it is popular among beginner rock collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz specifically is common because it is the most frequent variety of quartz found in hydrothermal veins.

Field identification & locations

Identify by its hardness (will scratch glass), lack of cleavage, and waxy/greasy luster on broken surfaces. Found globally in almost any geological environment, particularly in gravel pits and mountain veins.