A hydrous alumino silicate characterized by a three dimensional framework of Si04 and Al04 tetrahedra, cross-linked by the sharing of oxygen atoms being chemically balanced by a cation, usually sodium or calcium and of crystalline structure such that openings or pores allow access to a relatively large absorption area inside the crystal. The cation may be ion exchanged for other metal ions, ammonia, an amine or hydrogen. Zeolites may be activated for sorption by driving off the water of hydration. Note. Terms Recognized as being Zeolite include Analcite, Cancrinite, Chabazite, Clinotilolite, Cordierite, Edingtonite, Erionite, Faujasite, Ferrierite, Gmelinite, Heulandite, Laumontite, Levynite, Mesolite, Mordenite, Natrolite, Offretite, Paulingite, Phillipsite, Ptilolite, Scolecite, Thomsonite, ZSM, and ZK. Note. See the list in (3) Note of the definition of Clay, supra, for some silicon compounds not treated as clays or zeolites in this class (502).
For class 502