bentonite(redirected from E558)
Also found in: Thesaurus, Medical, Encyclopedia.
An absorbent aluminum silicate clay formed from volcanic ash and used in various adhesives, cements, and ceramic fillers.
[After Benton Formation of the Rock Creek district in eastern Wyoming.]
ben′ton·it′ic (-nĭt′ĭk) adj.
(Geological Science) a valuable clay, formed by the decomposition of volcanic ash, that swells as it absorbs water: used as a filler in the building, paper, and pharmaceutical industries
[C19: from Fort Benton, Montana, USA, where found, + -ite1]
a porous clay that swells to several times its dry volume when absorbing water.
[1895–1900; after Fort Benton, Montana]
ben•ton•it•ic (ˌbɛn tnˈɪt ɪk) adj.