mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Cloudy white to transluscent, Luster: Vitreous (glassy) to greasy, Crystal structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified March 1, 2026More mineral →

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Physical properties

Formation & geological history

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

Uses & applications

Used in construction as aggregate, as a source of silica for glass and ceramics, and in jewelry/lapidary as cabochons or tumbled stones. High-purity quartz is used in electronics.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It can sometimes contain microscopic 'bubbles' of water dating back millions of years. It is often found in gold-bearing veins.

Field identification & locations

Identified in the field by its hardness (cannot be scratched by steel), glassy appearance, and white cloudy color. It is nearly ubiquitous in mountain regions and river beds worldwide.