Milky Quartz

Silicon Dioxide (SiO2)

Rock Type: mineral

Milky Quartz

Physical Properties

Hardness: 7 (Mohs scale); Color: White, semi-opaque, or translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (Trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & Geological History

Formed through the crystallization of silica-rich hydrothermal solutions or within igneous pegmatites. 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 sandpaper, in sandblasting, and occasionally for landscaping or as a lapidary material for ornaments.

Geological Facts

Quartz is the second most abundant mineral in the Earth's continental crust. Milky quartz is often found in massive veins and can sometimes contain gold inclusions, which miners look for as a sign of precious metal deposits.

Field Identification & Locations

Identify by its ability to scratch glass (hardness) and the absence of cleavage planes. It often appears as chunky white masses in various environments including river beds, mountains, and desert plains.

Identified on: 4/16/2026

Mode: Standard