Metamorphic – rock formed by the effects of added heat or pressure to another rock. Not one of these definitions really fits because these definitions define processes! What we find is that with some types of stones it is that the forms that they take (like geodes, concretions, nodules, and many others) that we as geologist use to describe them.
How Does Breccia Differ From Conglomerate? Breccia and conglomerate are very similar rocks. They are both clastic sedimentary rocks composed of particles larger than two millimeters in diameter. The difference is in the shape of the large particles. In breccia the large particles are angular in shape, but in conglomerate the particles are rounded.