A pebble is a clast of rock with a particle size of 4–64 mm (0.16–2.52 in) based on the Udden-Wentworth scale of sedimentology. ... A rock made predominantly of pebbles is termed a conglomerate.

What kind of rock is a pebble?

Clastic sedimentary rocks may have particles ranging in size from microscopic clay to huge boulders. Their names are based on their clast or grain size. The smallest grains are called clay, then silt, then sand. Grains larger than 2 millimeters are called pebbles.

Is a small stone a rock?

Rocks are made of smaller stones and stones are made from rocks. Rocks can be described as a large piece of stone that is difficult to be carried in the hand. On the other hand, stone is just a small piece or pebble that can be carried in the hand. The rocks are heavier than stones.