sedimentary

Beach Pebbles and Quartz Aggregates

Quartz / Calcite Beach Pebbles (SiO2 / CaCO3)

AI-generated identification · may be incorrect

Hardness: 6-7 on Mohs scale for quartz portions; Luster: Waxy to vitreous, water-worn dull surface; Color: Off-white, yellowish, gray, cream, translucent white; Structure: Microcrystalline/massive pebbles tumbled by wave action; Cleavage: None to indistinct.

Hardness: 6-7 on Mohs scale for quartz portions
Color: Off-white, yellowish, gray, cream, translucent white
Luster: Waxy to vitreous, water-worn dull surface

Identified July 26, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through mechanical weathering and erosion by ocean waves and river currents. The pebbles are composed primarily of durable vein quartz, chalcedony, and calcium carbonate fragments, smoothed into rounded shapes over time in coastal environments.

Uses & applications

Mainly collected for hobbyist rock tumbling, beach souvenir collections, aquarium decor, landscape design, and educational identification.

Geological facts

Beach pebbles owe their smooth, rounded shapes to thousands of hours of abrasive grinding in coastal surf zones. Quartz is often the most abundant mineral surviving this intense weathering process due to its resistance to both chemical and physical erosion.

Field identification & locations

Identify by their rounded, water-smoothed contours and beach setting. Found along shorelines, ocean beaches, and riverbanks globally. Great starter specimens for rock tumblers.