- a soft very fine-grained whitish rock consisting of the siliceous remains of diatoms deposited in the ocean or in ponds or lakes. It is used as an absorbent, filtering medium, insulator, filler, etc
Collins Concise English Dictionary © HarperCollins Publishers::
diatomite /daɪˈætəˌmaɪt/ n
'diatomite' also found in these entries (note: many are not synonyms or translations):