bentonite dongo ufa ndi mchere wosakhala wachitsulo wokhala ndi montmorillonite monga gawo lalikulu la mchere. Kapangidwe ka montmorillonite ndi 2: 1 mtundu wamakristalo wopangidwa ndi ma silicon-oxygen tetrahedrons ndi ma aluminium-octahedrons. Pali mitundu ina yazomata, monga Cu, Mg, Na, K, ndi zina zambiri, ndipo kulumikizana kwa ma cations awa ndi montmorillonite unit cell ndikosakhazikika, ndipo ndikosavuta kusinthana ndi ma cation ena, kotero ali ndi kusintha kwabwino kwa ion. Maiko akunja agwiritsidwa ntchito m'madipatimenti opitilira 100 m'malo 24 opanga mafakitale ndi zaulimi, ndipo pali zopitilira 300, chifukwa chake anthu amatcha "nthaka yadziko lonse".