mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to translucent
Luster: Vitreous to greasy

Identified March 16, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal solutions in veins, or through the cooling of silica-saturated magma in igneous rocks like granite and pegmatites. Found across all geological ages.

Uses & applications

Used in the glass industry, as an abrasive, in electronics (piezoelectric properties), as a flux in metallurgy, and widely in landscaping and construction. Low-grade specimens are popular for amateur collectors.

Geological facts

Milky quartz gets its cloudy appearance from microscopic inclusions of fluids (gas or liquid) trapped during crystal growth. It is one of the most abundant minerals on the Earth's continental crust.

Field identification & locations

Identify in the field by its ability to scratch glass, lack of cleavage, and white 'milky' appearance. Commonly found in mountainous regions and riverbeds. It is a 'marker' mineral for potentially finding gold or other valuable ores in veins.