Answer:
Pumice is a light colored, porous igneous rock. It forms during volcanic eruption occurring under water. It is an aggregate of concrete. Because of their porous nature they float over the surface of water. With time the pumice rocks undergoes with several changes including weathering, erosion, and transportation. The extent of heat and pressure, making the sediments of the pumice rocks into metamorphic rocks distinct in the chemical and physical composition of the parent material.