mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Opaque white due to microscopic fluid inclusions. Luster: Vitreous to greasy. Crystal System: Trigonal. Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Opaque white due to microscopic fluid inclusions
Luster: Vitreous to greasy

Identified January 12, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: Opaque white due to microscopic fluid inclusions. Luster: Vitreous to greasy. Crystal System: Trigonal. Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Formation & geological history

Forms in hydrothermal veins and pegmatites. It is the most common variety of crystalline quartz, created as silica-rich fluids cool within earth's crustal cavities. It can be found in geological formations of almost any age, from Precambrian to recent.

Uses & applications

Used widely in the glassmaking and abrasive industries. Higher quality specimens are used for ornamental carvings, tumble polishing for jewelry, and as a source of silicon for electronics and solar panels. Also used as road gravel and construction aggregate.

Geological facts

Milky quartz gets its cloudy appearance from tiny bubbles of gas or liquid trapped during the crystal's growth. Some of the largest quartz crystals ever found have been 'milky' in appearance, weighing several tons.

Field identification & locations

Identify in the field by its distinct white color, inability to be scratched by a steel knife (it will scratch glass), and lack of cleavage (it breaks in irregular, curved shards). Found globally; look for it in mountainous regions or as pebbles in riverbeds and on beaches.