mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness 7 on Mohs scale; dull to glassy luster when wet; translucent to opaque grayish-purple/pinkish hue; smooth, rounded water-worn texture; conchoidal fracture.

Identified July 24, 2026More mineral →

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Physical properties

Hardness 7 on Mohs scale; dull to glassy luster when wet; translucent to opaque grayish-purple/pinkish hue; smooth, rounded water-worn texture; conchoidal fracture.

Formation & geological history

Formed through igneous crystallization or hydrothermal processes, subsequently weathered and rounded by alluvial, river, or ocean wave action over thousands to millions of years.

Uses & applications

Commonly collected as river pebbles, used in decorative landscaping, aquarium gravel, or polished in rock tumblers for jewelry and crafting.

Geological facts

Quartz is one of the most abundant minerals in Earth's continental crust. Rounded beach or river pebbles get their smooth shape from constant abrasion against other rocks in moving water.

Field identification & locations

Identified by its hardness (scratches glass), lack of cleavage, and smooth rounded shape. Very commonly found on beaches, riverbeds, and gravel pits worldwide.