Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Rock Type: mineral

Milky Quartz

Physical Properties

Hardness: 7 on Mohs scale; Color: Cloudy white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & Geological History

Formed from silica-rich hydrothermal solutions or cooling magma. Milky quartz gets its appearance from tiny fluid or gas inclusions trapped during crystal growth. Found in veins across all geological ages.

Uses & Applications

Used in electronics for its piezoelectric properties, as an abrasive, in glassmaking, and in landscaping or as a gemstone in costume jewelry.

Geological Facts

Milky quartz is the most common variety of crystalline quartz. While often overlooked for clearer varieties like rock crystal, massive veins of milky quartz can contain concentrated deposits of gold.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass), cloudy white appearance, and lack of cleavage. Common in mountainous regions, riverbeds, and as garden stones.

Identified on: 4/26/2026

Mode: Standard