Pebbles are simply defined as a loose piece of rock that can fit on the palm of your hand.
I really enjoy checking out pebbles particularly on coastal geology trips !
Also, we have the occasional cobble and boulder which are that bit bigger than a pebble.
Quartzite with chatter marks, Pebble beach West of Covesea, Moray
Nodules of barytes in Sandstone Hopeman Sandstone (Permian) East Hopeman Beach,