Pumice is a lightweight volcanic rock made of solidified lava that was violently ejected from the volcano. It is usually pale in color, but it is sometimes brown or black. It forms when the lava is rapidly cooled and depressurized, which leads to bubbles and makes the rock porous. It may also form when water mixes with lava. Pumice has a number of niche applications and is widely used throughout the world because it occurs naturally in many places.
Uses of pumice
Ground pumice is used as an mild abrasive in many situations. It is this quality that makes it suitable for use in household cleaners, polish, heavy duty soaps, pencil erasers and toothpaste. It is also be used in the cosmetic industry where it is used in many products designed to exfoliate the skin. Also in this industry the whole pumice rock can be used, where it is known as a pumice stone. These stones are used to remove calluses as well as excess and dry skin from the feet. The mild abrasive effect of a pumice stone is also used to clean porcelain, such as stains in toilets.
A type of pumice, called pozzolan, is mixed with lime to create lightweight concrete. This type of concrete has been used for many years and was used for many Roman constructions. Occasionally pumice is used to create lightweight concrete blocks used in the construction industry.