Microscopic skeletons of diatoms from prehistoric seas used for a filter bed for production of potable water and polishing of wastewater...

Diatomaceous earth (pronounced /ˌdaɪətəˈmeɪʃəs ˈɝθ/), also known as DE, TSS, diatomite, diahydro, kieselguhr, kieselgur and Celite) is a naturally occurring, soft, chalk-like sedimentary rock that is easily crumbled into a fine white to...