Claim: A quarry is where granular material has been excavated.

Gravel -LSB- ˈɡrævəl -RSB- is the study of rock fragments that have a general particle size range and include size classes from granule - to boulder-sized fragments . Gravel is categorized by the Udden-Wentworth scale into granular gravel -LRB- 2 to -RRB- and pebble gravel -LRB- 4 to -RRB- . One cubic metre of gravel typically weighs about 1,800 kg -LRB- or a cubic yard weighs about 3,000 pounds -RRB- .   Gravel is an important commercial product , with a number of applications . Many roadways are surfaced with gravel , especially in rural areas where there is little traffic . Globally , far more roads are surfaced with gravel than with concrete or tarmac ; Russia alone has over 400000 km of gravel roads . Both sand and small gravel are also important for the manufacture of concrete .