Crushed stone or angular rock is a form of construction aggregate, typically produced by mining a suitable rock deposit and breaking the removed rock down to the desired size using is distinct from gravel which is produced by natural processes of weathering and erosion, and typically has a more rounded shape.
FS. Natural AggregatesFoundation of America's Future. FS14497 (PDF) Recycled Aggregates Profitable Resource Conservation. FS18199. Open File Reports. Preliminary Report on Aggregate Use and Permitting Along the Colorado Front Range. OF000258.