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)
“The murmuring surge,
That on th’ unnumbered idle pebble chafes,
Cannot be heard so high.”
—William Shakespeare (1564–1616)
“What was that whiteness?
Truth? A pebble of quartz? For once, then, something.”
—Robert Frost (1874–1963)