Milky Quartz
Silicon Dioxide (SiO2)
Rock Type: mineral

Physical Properties
Hardness: 7 (Mohs scale); Color: White, opaque to translucent; 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 where gas or liquid bubbles are trapped during crystal growth, creating the 'milky' appearance.
Uses & Applications
Used in glass manufacturing, electronics (due to piezoelectric properties), abrasives, ornamental carvings, and low-cost jewelry/tumbled stones.
Geological Facts
Milky quartz is the most common variety of crystalline quartz. The white color is caused by tiny fluid inclusions of gas or liquid trapped during the crystal's formation.
Field Identification & Locations
Identify by its ability to scratch glass and lack of cleavage. It is found globally in pegmatites and hydrothermal veins. Collectors can find it in almost any mountainous or volcanic region.
Identified on: 4/30/2026
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