Zeolites are aqueous aluminosilicates of calcium, sodium, potassium, barium and other elements. The group of zeolites includes more than forty minerals, which differ both in composition (especially in the number of water molecules in the crystalline hydrate), and, of course, in physical and chemical properties. But almost all the group's representatives have a common property - they are good sorbents, have ion-exchange properties, may change the mobility of individual ions and act as molecular sieves.