Quartz (Milky Quartz)

Physical Properties

Hardness: 7 on Mohs scale; Color: Opaque white to slightly translucent cream; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (Trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & Geological History

Formed in hydrothermal veins and pegmatites. It precipitates from hot, silica-rich solutions as they cool or as pressure changes in the Earth's crust. It is a major component of nearly all igneous, metamorphic, and sedimentary rocks.

Uses & Applications

Used in electronics for piezoelectrical properties, as a glass-making ingredient, in abrasives, and commonly used as gravel in construction. Rough specimens like this are often collected by hobbyists.

Geological Facts

Milky quartz gets its cloudy appearance from microscopic inclusions of liquids or gases trapped during crystal formation. It is the most common variety of crystalline quartz on Earth.

Field Identification & Locations

Identify in the field by its ability to scratch glass and lack of cleavage. It is found globally in riverbeds, mountains, and beaches. Look for its characteristic 'sugary' or glassy texture on broken surfaces.

Identified on: 4/16/2026

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