Crushed Stone and Gravel
Crushed rock (mainly limestone and granite), sand, and gravel are so essential to urban life that billions of dollars worth are produced each year. They're used in concrete, roads, and virtually all construction sites. Sand and gravel cover the paths of the National Mall.
Image Number: 2002-11839
Catalog Number: Unaccessioned
Locality: National Mall, Washington
, District of Columbia