Milky Quartz

Physical Properties

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

Formation & Geological History

Formed through the cooling and crystallization of silica-rich magma or from hydrothermal veins. The 'milky' appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & Applications

Used in the manufacturing of glass and ceramics, as an abrasive, in the semiconductor industry for silicon, as decorative landscaping stone, and occasionally in jewelry as cabochons.

Geological Facts

Quartz is the most abundant and widely distributed mineral found at Earth's surface. Milky quartz is the most common variety of crystalline quartz. It is often found associated with gold in hydrothermal vein deposits.

Field Identification & Locations

Identify in the field by its hardness (it scratches glass but isn't scratched by steel), its white/cloudy appearance, and lack of cleavage. Look for it in mountainous regions or as rounded pebbles in stream beds.

Identified on: 4/20/2026

Mode: Standard