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 through the crystallization of silica-rich hydrothermal solutions or cooling magma in pegmatites. The milky white color is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & Applications

Used in electronics as a source of high-purity silica, as an abrasive, in glassmaking, as decorative landscaping stone, and as tumbled gemstones for collectors.

Geological Facts

Milky quartz is one of the most common varieties of crystalline quartz on Earth. While less popular than amethyst or rose quartz, it represents the majority of vein quartz found globally.

Field Identification & Locations

Identify by its hardness (scratches glass), lack of cleavage, and 'cloudy' appearance. It is often found as veins in igneous and metamorphic rocks. Collectors should look for large, well-defined crystal faces in pegmatite zones.

Identified on: 5/16/2026

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