What is diatomite?

   Diatomite is a lightweight, fine-grained, soft, sedimentary rock that resembles chalk. It is often called diatomaceous earth or kieselguhr.
   Diatomite consists of the fossilized siliceous shells of diatoms, a type of algae. Its chief use is as an indus­trial filter for beverages, sugars, and oils and for water purification. Diatomite is also excellent as a filler for paints and plastimisccs, as an abrasive, and as insulating material. Deposits are widely distributed in Europe and the United States. The largest known deposit is near Lompoc, Calif., where beds up to 1,400 feet thick are mined. The United States, France, and West Germany lead in production.