mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to light grey; Luster: Vitreous (glassy) to waxy when wet; Crystal structure: Trigonal/Hexagonal (cryptocrystalline in this form); Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to light grey
Luster: Vitreous (glassy) to waxy when wet

Identified March 24, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in veins or from the crystallization of magma. This specific specimen is a 'river rock' or 'tumble stones' pebble, shaped and smoothed by water erosion over thousands of years.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative gravel or landscaping stones. Polished versions are common in beginner rock collections and metaphysical use.

Geological facts

Milky quartz gets its cloudy appearance from tiny fluid inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth's crust.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife, its white 'milky' opacity, and its smooth, rounded texture if found near water. It is ubiquitous in gravel beds, beaches, and mountain streams worldwide.

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