Large polished black pebbles on seashore of Rivière des Galets

A pebble is a fragment of rock with a rounded, smooth appearance. Pebbles are erosion products that are transported by rivers: by rubbing with other fragments, the rocks become smooth; rolled, the pebbles take their rounded shape (fluvial pebbles). They accumulate in the beds of rivers, deltas and the sea. There are also marine pebbles, formed of rock fragments tossed about by currents and waves, thus undergoing wear similar to that of fluvial pebbles. These pebbles are found on beaches, often mixed with fluvial pebbles like here at Rivière des Galets in Mauritius. The reflection of the sun on the pebbles while it is rising offers a spectacular view.