Breccias are rocks that are composed of a mixture of different-sized, angular fragments held together by a matrix. Synonyms for the term "breccial" include: conglomerate, rubble, debris, jumble, and agglomerate. Conglomerate refers to a rock consisting of rounded fragments embedded in a matrix. Rubble is a term used to describe broken fragments of stone or other materials. Debris is any scattered remains or remains of a structure. Jumble refers to something that is mixed haphazardly, as in a pile of rocks. Lastly, agglomerate refers to a rock composed of pebbles, boulders, or other fragments held together by a cementing material.