mineral

Cloudy Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: Translucent to opaque white. Luster: Vitreous (glassy) to greasy. Crystal structure: Trigonal/Hexagonal. Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Translucent to opaque white
Luster: Vitreous (glassy) to greasy

Identified March 11, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of magma or by hydrothermal activity where water rich in silica deposits crystals in veins and cavities. It occurs in all geological ages from the Archean to the Holocene.

Uses & applications

Used widely in glassmaking, as an abrasive in sandblasting, in the manufacturing of silicon chips for electronics, and as decorative stone or gravel in landscaping. High-quality specimens are used in jewelry and metaphysical collecting.

Geological facts

Milky quartz gets its cloudy appearance from minute fluid inclusions of gas and/or liquid trapped during crystal growth. It is the most common variety of crystalline quartz found on Earth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and translucent white appearance. It is found globally, often in mountain ranges or as pebbles in riverbeds. Beginners should look for its distinctive greasy luster when broken.

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