mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

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

Identified July 18, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins and pegmatites through the cooling of silica-rich hot fluids. It is also a primary constituent of granite and many metamorphic rocks.

Uses & applications

Used as a decorative aggregate in landscaping, as a source for silicon in semiconductor manufacturing, in glassmaking, and as a low-cost collector mineral.

Geological facts

Milky quartz gets its cloudy appearance from tiny fluid or gas inclusions trapped during crystal growth. It is the most common variety of crystalline quartz found on Earth's surface.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass), its white translucent color, and its lack of cleavage planes. It is often found as rounded pebbles in gravel or as angular chunks in rocky outcrops.