Diatomaceous earth Wikipedia
Diatomaceous earth / ˌ d aɪ ə t ə ˌ m eɪ ʃ ə s ˈ ɜːr θ / diatomite or kieselgur/kieselguhr is a naturally occurring soft siliceous sedimentary rock that has been crumbled into a fine white to off white powder It has a particle size ranging from less than 3 μm to more than 1 mm but typically 10 to 200 μm Depending on the granularity this powder can have an abrasive feel