mineral

Milky Quartz (Tumbled Pebble)

Silicon Dioxide (SiO2)

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

Hardness: 7 (Mohs scale)
Color: Translucent white to milky
Luster: Vitreous to waxy

Identified July 7, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms through the crystallization of silica-rich hydrothermal fluids in veins or as a primary mineral in igneous rocks like granite. This specific piece is a water-worn or tumbled pebble, likely weathered out of a host rock and smoothed over thousands of years.

Uses & applications

Used primarily for ornamental purposes, landscaping, tumbled stone collections, and as a source of silica in glassmaking or electronics if found in high purity.

Geological facts

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

Field identification & locations

Identified by its hardness (can scratch glass), white color, and lack of cleavage. Commonly found in riverbeds, beaches, and mountainous regions worldwide. Collectors look for pieces with interesting patterns or high translucency.