Diatomite is also known as Diatomaceous Earth, Kieselguhr, Kieselgur, and Celite. It is a naturally occurring, soft, chalk-like, sedimentary rock and is primarily composed of the fossilized remains of unicellular fresh water plants, Diatoms. The powder has abrasive feeling which is similar to pumice powder. It is very light-weight because of its porosity.