... powder, metal luster, hardness of 3 to 5, the relative density of 2 to 2.8, a color of natural zeolite, synthetic zeolite as ... a white, insoluble in water, thermal stability and acid resistance as the SiO2 / Al2O3 ... composition ratio increases. 2. Zeolite have great surface area, up to 300 ~ 1000m2 / g, a high degree of polarization ...