| a fine siliceous earth composed chiefly of the cell walls of diatoms: used in filtration, as an abrasive, etc. |
diatomaceous earth di·a·to·ma·ceous earth (dī'ə-tə-mā'shəs, dī-āt'ə-)
n.
A powder made of the desiccated shells of diatoms, used as a filtering agent, adsorbent, and abrasive in many chemical operations.
| diatomite (dī-āt'ə-mīt') Pronunciation Key
A fine, light-colored, friable sedimentary rock consisting mainly of the silica-rich cell walls of diatoms. Diatomite forms both in lacustrine and marine environments. It is used in industry as a filler, filtering agent, absorbent, abrasive, and insulator. |