Diatomaceous Earth

Diatomaceous Earth, powdery natural material formed almost entirely from the skeletons of diatoms, deposited in most cases during the Cenozoic era. It is usually extremely fine in texture and gray or white in color. When pure, diatomaceous earth is composed almost entirely of silicon dioxide or silica, but it is often found mixed with clay or organic matter. The material is used extensively as an abrasive, a filtering material, an inert ingredient of explosives, and an insulating material for boilers and steam pipes. When diatomaceous earth is found compacted into a chalky solid rock, it is known as diatomite or tripoli. Deposits of diatomaceous earth are found in many parts of the world. The thickest known deposit, over 300 m (over 1000 ft) in depth, is in California.


"Diatomaceous Earth," Microsoft® Encarta® Online Encyclopedia 2000

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