What fossil is a copy of an organism's structure, formed when minerals seep into a mold in sediment?

Cast is a fossil that is a copy of an organisms shape, formed when minerals seep into a mold. A fossil formed when an animal, plant, or other organism dies, its flesh decays and bones deteriorate due to chemical reactions; minerals gradually enter into the cavity, resulting in a cast, also called a mold fossil, which is in the general form of the original organism.