mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

Identified April 14, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. The milky appearance is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth. They are found across all geological ages.

Uses & applications

Used in glassmaking, abrasives, as a flux in metallurgy, in electronics for its piezoelectric properties, and as decorative gravel or gemstones.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of quartz and can often be found in large veins that are visible on the surface of landscapes.

Field identification & locations

Identify by its hardness (it will scratch glass), its white 'milk-like' opacity, and lack of cleavage. Look for it in mountainous regions, riverbeds, and as veins in metamorphic or igneous rock outcrops.