Diatomaceous earth - Wikipedia
Diatomaceous earth (/ ˌ d aɪ. ə t ə ˌ m eɪ ʃ ə s ˈ ɜːr θ /, DE), diatomite or kieselgur/kieselguhr is a naturally occurring, soft, siliceous sedimentary rock that is easily 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 ...