|Analcime - NaAlSi2O6H2O.|
|Chabazite - Ca(Al2Si4)O12 6H2O.|
Zeolites are hydrated aluminosilicates of the alkaline and alkaline-earth metals. About 40 natural zeolites have been identified during the past 200 years; the most common are analcime, chabazite, clinoptilolite, erionite, ferrierite, heulandite, laumontite, mordenite, and phillipsite. Commercial zeolite deposits in the United States are associated with the alteration of volcanic ash beds. Zeolites mined in a few Western States satisfy domestic requirements. More than 150 zeolites have been synthesized; the most common are zeolites A, X, Y, and ZMS-5. Natural and synthetic zeolites are used commercially because of unique adsorption, catalytic, ion-exchange, and molecular sieve properties. Animal feed, horticultural applications, and pet litter account for most sales of zeolites.