The physical properties of faujasites (FAU) as well as of EMT-FAU type frameworks are analysed in this volume. Faujasite type zeolites have a wide range of industrial applications as ion exchanger, sorption agent, molecular sieve and as a catalyst, due primarily to their excellent structural stability, large and accessible pore volume, high activity, high resistance to nitrogen compounds and high regenerability. Important industrial processes, where faujasites are used as catalysts, are cracking, hydrocracking and isomerization for obtaining petroleum products from crude oil.