Template:POTD/2012-03-02
Diatomaceous earth – a naturally occurring, soft, siliceous sedimentary rock made up of the cell walls/shells of single cell diatoms – as viewed under bright field illumination on a light microscope. The primary uses of diatomaceous earth are for cleaning (scouring), filtration, heat-resistive insulation and as an inert absorbent substrate.Photo: Richard Wheeler