mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Opaque white to translucent, Luster: Vitreous to greasy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified May 26, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Opaque white to translucent, Luster: Vitreous to greasy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed via hydrothermal activity where silica-rich fluids cool in veins or as massive deposits. This specific specimen is a water-worn river pebble, rounded by mechanical weathering over long periods.

Uses & applications

Used in landscaping, construction aggregate, glass making, and as decorative stones for collectors or aquarium use.

Geological facts

The milky appearance is caused by tiny inclusions of gas and liquid trapped during the crystal's formation. It is one of the most common mineral varieties on Earth's crust.

Field identification & locations

Identify in the field by its white color, ability to scratch glass (hardness 7), and water-worn smooth texture. Found globally in riverbeds, beaches, and mountain trails.