Pumice is a form of volcanic rock that contains numerous cavities on its surface and throughout its interior. The cavities are created as a result of rapid cooling and depressurization. Bubbles form by gases in the volcanic lava, and the bubbles are frozen by rapid cooling after the pumice is ejected from the volcano.
Because of its porosity, pumice is well-suited for use in creating low-density cinder blocks. Pozzolan, a fine version of pumice, can be mixed with lime to create a type of lightweight concrete that has been used since Roman times. Pumice stone is often used to slough off dead skin during a pedicure. It is also used in heavy-duty hand soaps as well as in some toothpastes.Learn more about Geology