mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Milky white to translucent off-white
Luster: Vitreous to greasy

Identified July 22, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in hydrothermal veins, pegmatites, and metamorphic rocks where silica-rich fluids cool and crystallize slowly. Tiny fluid gas bubbles trapped within the crystal lattice give it its cloudy white appearance.

Uses & applications

Used in glassmaking, abrasives, ceramics, petroleum industry (proppant), electronics, and as decorative gravel or ornamental stone.

Geological facts

Milky quartz is one of the most common minerals on Earth's surface. The milky white color is caused by millions of microscopic fluid inclusions of water or gas trapped during crystal growth.

Field identification & locations

Look for a hard, cloudy white or off-white mineral that scratches glass and steel easily, lacks cleavage, and displays a greasy to vitreous luster. Commonly found in gravel beds, mountain regions, stream beds, and pegmatites worldwide.