O le vai o loʻo i totonu o le montmorillonite e fesuisuiaʻi ma faʻateleina tele pe a mitiia le vai. O vailaʻau, o le hydrated sodium calcium aluminium magnesium silicate hydroxide (Na,Ca) 0.33 ((Al,Mg) 2 ((Si4O10) ((OH) 2 · nH2O. Potassium, uʻamea, ma isi cations o ni sui masani, ma o le saʻo o le faʻatusatusaga o cations e fesuisuiaʻi ma le mafuaʻaga. E masani ona fefiloi ma chlorite, muscovite, illite, cookeite, ma kaolinite. Fesili: O a nisi o sui masani?
Potassium, iron, ma isi cations