Milky Quartz
Silicon Dioxide (SiO2)
Rock Type: mineral

Physical Properties
Hardness: 7 (Mohs scale), Color: White to translucent waxy white, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65
Formation & Geological History
Formed from silica-rich hydrothermal fluids cooling in igneous veins or pegmatites; milky appearance is caused by tiny fluid inclusions trapped during crystal growth. Can be found in rocks of various geological ages.
Uses & Applications
Used in electronics as a source of high-purity silica, as landscaping stone, in glass manufacturing, and as decorative garden boulders.
Geological Facts
Milky quartz is the most common variety of crystalline quartz. Historically, it was sometimes used by prehistoric cultures for toolmaking when finer materials like flint were unavailable.
Field Identification & Locations
Identify in the field by its distinct white color, inability to be scratched by steel, and lack of cleavage planes. Found globally in mountainous regions and riverbeds.
Identified on: 4/25/2026
Mode: Standard