mineral

Quartz (Milky Quartz pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Opaque white to cream-colored; Luster: Vitreous to waxy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Opaque white to cream-colored
Luster: Vitreous to waxy

Identified March 18, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale; Color: Opaque white to cream-colored; Luster: Vitreous to waxy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & geological history

Formed from the cooling of silica-rich magma or from hydrothermal veins. This specific specimen is a 'river pebble,' meaning its rounded shape is the result of mechanical weathering and erosion over thousands of years in a high-energy water environment.

Uses & applications

Milky quartz is used in the manufacture of glass and ceramics, as an abrasive, and in the production of silicon for electronics. Rounded pebbles are commonly used in landscaping and as decorative garden mulch.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its cloudy appearance from microscopic inclusions of fluids or gas trapped during the crystal's growth.

Field identification & locations

Identify in the field by its ability to scratch glass and its lack of cleavage. It is found globally in riverbeds, beaches, and soil. To verify, look for its translucent-to-opaque white color and smooth, water-worn texture.

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