mineral

Quartz (Milky or Cloudy variety)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to greyish-white (milky), translucent; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to greyish-white (milky), translucent
Luster: Vitreous to greasy

Identified March 16, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes, crystallization from magma, or within metamorphic rocks. Quartz is ubiquitous across geological ages and environments, often found in veins where silica-rich fluids cooled slowly.

Uses & applications

Used extensively in glassmaking, electronics (piezoelectric properties), abrasives, and as a raw material in concrete and mortar. Larger, clearer specimens are used in jewelry and specialized glass. Common rough specimens are mostly decorative for collections.

Geological facts

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

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), lack of cleavage, and characteristic waxy or glassy luster. Commonly found in riverbeds, mountain gravel, and rocky outcroppings globally.

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