Molecular formula: MxOy [Alx + 2ySin- (x + 2y) O2n] · mH2O. Properties: A wide range of silicate minerals. It consists of a three-dimensional lattice of silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons connected by a common oxygen. The excess negative charge generated by trivalent aluminum replacing tetravalent silicon consists of monovalent or divalent metal cations, usually alkali metals or alkaline earth Balanced by metal cations.
Zeolites are divided into cristobalite Na [AlSi2O6] · H2O and calcium zeolite Ca [Al2Si3O10] · 3H2O due to different components. Its water content is related to the outside temperature and the pressure of water vapor. When heated, the water can escape slowly, but it does not destroy its crystal structure. Generally light color, glass gloss, hardness 3-3.5, specific gravity 2.0-2.4.