Milky Quartz

Physical Properties

Hardness: 7 on Mohs scale; Color: Opaque white; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & Geological History

Formed through the crystallization of silica-rich hydrothermal veins or from the cooling of magma in igneous rocks. The milky color is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & Applications

Used in glassmaking, as an abrasive, in the production of silicon for electronics, as landscaping stone, and occasionally in jewelry or as a decorative collector's item.

Geological Facts

Milky quartz is the most common variety of crystalline quartz. Historically, it was used by many indigenous cultures to create sharp stone tools and spearheads when flint was unavailable.

Field Identification & Locations

Identify in the field by its ability to scratch glass, its milky white opacity, and the absence of cleavage planes. Found globally in almost all geological environments.

Identified on: 4/26/2026

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