Pebble
A pebble is a clast of rock with a particle size of 4 to 64 millimetres based on the Krumbein phi scale of sedimentology. Pebbles are generally considered to be larger than granules (2 to 4 millimetres diameter) and smaller than cobbles (64 to 256 millimetres diameter). A rock made predominantly of pebbles is termed a conglomerate. Pebble tools are among the earliest known man-made artifacts, dating from the Palaeolithic period of human history.
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Famous quotes containing the word pebble:
“A good intention clothes itself with sudden power. When a god wishes to ride, any chip or pebble will bud and shoot out winged feet and serve him for a horse.”
—Ralph Waldo Emerson (1803–1882)
“I do not know what I may appear to the world; but to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.”
—Isaac Newton (1642–1727)
“The murmuring surge,
That on th’ unnumbered idle pebble chafes,
Cannot be heard so high.”
—William Shakespeare (1564–1616)