mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Off-white to light yellowish-tan, opaque to translucent. Luster: Vitreous to greasy. Fracture: Conchoidal. Crystal Structure: Hexagonal (trigonal).

Hardness: 7 on Mohs scale
Color: Off-white to light yellowish-tan, opaque to translucent
Luster: Vitreous to greasy

Identified July 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: Off-white to light yellowish-tan, opaque to translucent. Luster: Vitreous to greasy. Fracture: Conchoidal. Crystal Structure: Hexagonal (trigonal).

Formation & geological history

Formed in hydrothermal veins and pegmatites through the slow crystallization of silica-rich solutions. This pebble has been rounded and smoothed through erosion in riverbeds or coastal environments.

Uses & applications

Used widely in landscape decoration, glass manufacturing, electronics, and as abrasive material. Small river pebbles are commonly collected by rockhounding enthusiasts.

Geological facts

Milky quartz gets its cloudy white appearance from tiny gas or liquid bubbles trapped within the crystal structure during its formation millions of years ago.

Field identification & locations

Identified by its hardness (scratches glass easily), lack of cleavage, and light color. Found abundantly in gravel beds, streams, and beaches worldwide.