Milky Quartz

Silicon Dioxide (SiO2)

Rock Type: mineral

Milky Quartz

Physical Properties

Hardness: 7 on Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); 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 microscopic inclusions of fluids or gas trapped during the crystal's growth.

Uses & Applications

Used in glassmaking, abrasives, electronics (piezoelectric properties), various industrial fillers, and as a semi-precious gemstone for carvings or tumbled stones.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz specifically is the most common variety of crystalline quartz found in nature.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and white, cloudy appearance. It is found globally, often in mountain ranges and riverbeds.

Identified on: 4/23/2026

Mode: Standard