Sinonimi: crushed rock
ETYM Old Fren. gravele, akin to French gr?ve a sandy shore, strand; of Celtic origin; cf. Armor. grouan gravel, W. gro coarse gravel, pebbles, and Skr. grâvan stone.
Rock fragments and pebbles; SYN. crushed rock.
Coarse sediment consisting of pebbles or small fragments of rock, originating in the beds of lakes and streams or on beaches. Gravel is quarried for use in road building, railroad ballast, and for an aggregate in concrete. It is obtained from quarries known as gravel pits, where it is often found mixed with sand or clay.
Some gravel deposits also contain placer deposits of metal ores (chiefly tin) or free metals (such as gold and silver).