Milky Quartz

Silicon Dioxide (SiO2)

Rock Type: mineral

Milky Quartz

Physical Properties

Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous to greasy; Crystal structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & Geological History

Formed from cooling magma or precipitation from hydrothermal fluids in veins. Common in igneous and metamorphic environments, and as a durable component in sedimentary sand.

Uses & Applications

Used in glass making, ceramics, as an abrasive, and in the production of silicon wafers for electronics. Occasionally used for decorative landscaping or low-grade jewelry.

Geological Facts

Milky quartz gets its cloudy appearance from minute fluid inclusions of gas or liquid trapped during crystal growth. It is the most common variety of crystalline quartz.

Field Identification & Locations

Identify by its white color, inability to be scratched by a steel knife, and lack of cleavage planes. Found globally, especially in mountain ranges and riverbeds.

Identified on: 5/16/2026

Mode: Standard