Milky Quartz

Physical Properties

Hardness: 7 on the Mohs scale; Color: Cloudy white to semi-translucent; Luster: Vitreous (glassy) to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & Geological History

Formed from silica-rich hydrothermal solutions or the cooling of magma in igneous rocks. The milky appearance is caused by tiny fluid or gas bubbles trapped during crystal growth. They can be found in formations ranging from billions of years old to relatively recent geological eras.

Uses & Applications

Used in glass making, abrasive manufacturing, as a source of silicon for electronics, in jewelry (cabochons), and as landscaping stones or decorative collector pieces.

Geological Facts

Milky quartz is the most common variety of crystalline quartz. While often overlooked by gem hunters in favor of clear quartz, it is responsible for the 'white' veins seen in many mountain ranges and is frequently associated with gold deposits.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass), cloudy white translucency, and lack of cleavage planes. It is found globally, particularly in pegmatites, hydrothermal veins, and as river pebbles.

Identified on: 4/16/2026

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