mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Milky white to light tan, Luster: Vitreous to waxy (weathered), Crystal structure: Hexagonal/Trigonal (though water-worn), Cleavage: None (Conchoidal fracture), Specific gravity: 2.65

Identified May 23, 2026More mineral →

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Physical properties

Formation & geological history

Quartz is formed through crystallization from magma or by precipitation from hydrothermal veins. This specific specimen has been smoothed and rounded by rolling in water (river or beach action) over years to decades.

Uses & applications

Industrial use in glassmaking, electronics (piezoelectric properties), abrasives, and as a common decorative landscape stone.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is extremely resistant to chemical weathering, which is why quartz pebbles are so common in riverbeds.

Field identification & locations

Identify by its hardness (it will scratch glass and metal) and its lack of cleavage. Found in riverbeds, beaches, and gravel pits worldwide. Collectors value it for tumbling or as a basic specimen for beginners.