mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: White to opaque milky white. Luster: Vitreous to greasy. Crystal system: Trigonal. Cleavage: Indistinct/Conchoidal fracture. Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: White to opaque milky white
Luster: Vitreous to greasy

Identified July 5, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: White to opaque milky white. Luster: Vitreous to greasy. Crystal system: Trigonal. Cleavage: Indistinct/Conchoidal fracture. Specific Gravity: 2.65.

Formation & geological history

Forms in hydrothermal veins and pegmatites when silica-rich fluids cool. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. Can be found in rocks of all geological ages.

Uses & applications

Used as an abrasive, in glass making, as a source of silicon for electronics, and widely as a landscaping or decorative stone.

Geological facts

Milky quartz is the most common variety of crystalline quartz. While often overlooked for clearer varieties like rock crystal, it can contain microscopic gold inclusions in certain geological settings.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass), its white color, and its lack of true cleavage. It is ubiquitous in mountainous regions and streambeds.