mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Milky white to light grey
Luster: Vitreous to greasy

Identified July 16, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to light grey; 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 opacity is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used as a gemstone, in glassmaking, as a source of silicon for electronics, and widely as a decorative stone or landscaping material.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It can often be found in large veins that are meters wide, sometimes containing traces of gold.

Field identification & locations

Identify by its hardness (will scratch glass), lack of cleavage, white color, and grainy or glassy texture. It is ubiquitous in riverbeds and mountainous regions globally.