mineral

Quartz Pebble

Silicon Dioxide (SiO2)

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

Hardness: 7 (Mohs scale)
Color: Translucent tan to smoky grey
Luster: Vitreous to waxy

Identified June 24, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through crystallization of silica-rich magma or precipitation from hydrothermal fluids. This specific specimen has been water-worn, likely in a river or beach environment, giving it a rounded, smooth texture.

Uses & applications

Common quartz pebbles are used as decorative garden stone, in construction aggregates, and for glass manufacturing if high purity. Smooth pebbles are often used in massage therapy or hobbyist stone tumbling.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. This specimen is a 'water-worn' river pebble which has naturally traveled miles from its source to achieve its rounded shape.

Field identification & locations

Identify in the field by its hardness (cannot be scratched by a steel blade) and lack of cleavage planes. Found globally in riverbeds, beaches, and glacial deposits.