mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

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

Hardness: 7 on Mohs scale
Color: Milky white to opaque
Luster: Vitreous (glassy) to waxy

Identified April 26, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through hydrothermal activity or crystallization from cooling magma (igneous veins). This specific specimen appears to be water-worn, smoothed by river or coastal erosion over thousands of years.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative landscaping stone. Polished versions are often used in low-cost jewelry or as 'worry stones'.

Geological facts

Milky quartz gets its white color from tiny bubbles of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz on Earth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), white color, and lack of cleavage. Common in riverbeds, beaches, and mountain trails worldwide.