mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to translucent
Luster: Vitreous to waxy

Identified March 14, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to translucent; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal solutions or cooling magma. This specific specimen is a water-worn river pebble, shaped by erosion and transport over thousands of years. Common in all geological ages.

Uses & applications

Industrial use in glassmaking, abrasives, and electronics (piezoelectric). Also used as decorative landscaping stones, tumbled pocket stones, or in jewelry as cabochons.

Geological facts

The milky white color is caused by tiny inclusions of gas or liquid trapped during the crystal's formation. It is the most common mineral found on the Earth's continental crust.

Field identification & locations

Identified in the field by its ability to scratch glass, lack of cleavage, and smooth, rounded water-worn surface. Found globally in riverbeds, beaches, and glacial deposits.