Bentonite, izwi kandi nka bentonite clay cyangwa montmorillonite clay, ni amabuye y'agaciro akomoka mu ibumba asanzwe agizwe ahanini na montmorillonite. Azwiho kuba afite ubushobozi bwo kwinjiza amazi mu buryo budasanzwe, ubushobozi bwo kubyimba, no guhanahana amakuru. Izina "Bentonite" rikomoka mu gace ka Benton muri Wyoming, muri Amerika, aho aya mabuye y'agaciro yihariye y'ibumba yavumbuwe bwa mbere kandi akitirirwa aho yavumbuwe.

Bentonite irangwa n'ubushobozi bwayo bwo gukora gel iyo inyoye amazi, ibi bigatuma igira agaciro gakomeye mu nganda zitandukanye. Imiterere yayo ifatika n'imiti ituma ikoreshwa nk'igice cy'ingenzi mu gucukura ibyondo, yongera ubukana bwabyo, imiterere yabyo, n'uburyo biryoha. Mu nganda z'impapuro, bentonite ikora nk'umusemburo wuzuza no gusiga, yongera ubwiza bw'impapuro, uburyo bworoshye bwo gucapa no gucapa. Byongeye kandi, ikoreshwa mu byuma, ibumba, amavuta yo kwisiga, n'ibindi, aho ishobora gukenerwa mu buryo butandukanye kandi hamwe n'ibisabwa byihariye mu mikorere.

Ibara rya bentonite rishobora kuva ku ryera n'umuhondo wijimye kugeza ku mabara atandukanye arimo imvi, icyatsi kibisi, umutuku, umukara n'umutuku, bitewe n'ingano yabyo y'icyuma. Akenshi igaragaza ubwiza nk'ubushyuhe, nk'ubutaka, cyangwa amavuta kandi rishobora kuboneka mu buryo buto n'ubunini. Ubushobozi bwa bentonite bwo kwinjiza bigira ingaruka zikomeye ku bunini bw'uduce twayo, aho uduce duto cyane tugaragaza kwinjiza ubwinshi.