Pumice rock is found all over the planet and on every continent. This textured rock is formed when volcanoes erupt, and it is carried from shore to shore after being generated by underwater volcanoes. The molten rock combines with water and air underground, and it erupts as a frothy liquid from vents in the Earth's surface. This hot frothy rock solidifies into hard, airy pumice stones.
Since a large amount of pumice is formed under seas and oceans, it is common for it to wash ashore and to be discovered on beaches. However, there are also many land-locked places where pumice is found. A large amount of pumice was created when Mount St. Helens erupted, and the eruption of Mount Pinatubo in the Philippines in 1991 generated many cubic miles of material, much of which was pumice.
Pumice is excavated and shipped all over the world for use in architecture, concrete manufacturing, cosmetics and the production of filtration media for water treatment systems. It is also used to aerate soils for agricultural use, and it is prized for its ability to retain water. One of the largest distributors of pumice stone is found in Idaho. Pumice from this region is prized because of its high purity and desirable color. It is shipped as far as Europe and Asia after it is mined, dried and refined.