Milky Quartz

Physical Properties

Hardness: 7 on Mohs scale; Color: White to creamy; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal system); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & Geological History

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a constituent of various rock types. The milky appearance is caused by tiny fluid inclusions trapped during crystal growth.

Uses & Applications

Used as an abrasive, in glass making, and as a decorative stone in landscaping. High-purity quartz is used in electronics and clocks (piezoelectricity).

Geological Facts

Milky quartz is the most common variety of crystalline quartz. It can sometimes contain traces of gold when found in hydrothermal 'auriferous' veins.

Field Identification & Locations

Identify by its ability to scratch glass and its lack of cleavage. It is commonly found in riverbeds, mountains, and as garden gravel. Collectors should look for unique shapes or associations with other minerals.

Identified on: 5/14/2026

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