bentonite yumbu foda shine ma'adanai marasa ƙarfe tare da montmorillonite a matsayin babban ɓangaren ma'adinai. Tsarin montmorillonite shine tsarin lu'ulu'u na 2: 1 wanda ya ƙunshi silicon-oxygen tetrahedrons da farantin aluminum-oxygen octahedrons. Akwai wasu cations a cikin tsararren tsari, kamar Cu, Mg, Na, K, da dai sauransu, kuma hulɗar waɗannan cations ɗin tare da sel na montmorillonite yana da tsayayye sosai, kuma yana da sauƙin musayar wasu cations, don haka yana da musayar ion mai kyau. An yi amfani da ƙasashen waje a cikin ɓangarori sama da 100 a yankuna 24 na samar da masana'antu da aikin gona, kuma akwai samfura sama da 300, don haka mutane ke kiransa "ƙasa ta duniya."