mineral

Milky Quartz

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: Cloudy white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

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

Identified July 13, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Cloudy white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids or within igneous pegmatites. The milky appearance is caused by microscopic inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used as a major source of silicon, in glassmaking, as an abrasive, and widely in jewelry or home decor as tumbled stones.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Historically, it was used by ancient civilizations for tools and sharp edges before the widespread use of metal.

Field identification & locations

Identify by its waxy luster, hardness (will scratch glass), and lack of cleavage. Often found near granite outcrops or in stream beds as rounded pebbles.