Crushed Stone, Sand, and Gravel Mining and Quarrying
Production Process. Gravel, sand and crushed rock are quarried out of rocky areas of land. Depending on the nature of the land, certain quarries are more suited to gravel, while others are more suited to sand or to rock.
Construction aggregate, or simply "aggregate", is a broad category of coarse to medium grained particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates.