Pebble
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A pebble is a clast of rock with a particle size of 4–64 mm based on the Udden-Wentworth scale of sedimentology. Pebbles are generally considered larger than granules and smaller than cobbles. Pebble
Close view of pebbles
Differently sized rocks and pebbles on a beach in northern England
Pebbles on a riverbank
A walkway decorated with pebbles set into concrete
Cobble (geology)
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A cobble is a clast of rock defined on the Udden–Wentworth scale as having a particle size of 64–256 millimeters, larger than a pebble and smaller than a boulder. Other scales define a cobble's size d
Pebble
…Udden-Wentworth scale of sedimentology. Pebbles are generally considered larger than granules (2–4 mm (0.079–0.157 in) in diameter) and smaller than cobbles (64–256 mm (2.5–10.1 in) in diameter). Pebble tools are among the earliest known man-made artifacts, dating from the Palaeolithic period of human…
Beach cobbles (Nash Point, Wales)
Sandy conglomerate with cobbles in the Hazeva Formation (Miocene) of southern Israel
Fernando noronha