breccia

This term is used primarily in geological and petrological contexts to describe a specific type of fragmented rock. It is distinguished from conglomerate, which consists of rounded fragments; breccia specifically implies angular, sharp-edged pieces, indicating that the fragments were not transported far from their source before being cemented.

In a technical sense, the word is often used as an uncountable mass noun when referring to the material generally, though it can be used countably when referring to specific types or deposits of the rock.