Natrolite and Analcime in Altered Volcanic Rocks of Davazdah Emam, northern Central Iran

Minerals identified in the Davazdah Emam region in order of their genesis include smectite, calcite, analcime, natrolite, mesolite, scolcite and quartz. Formation of zeolite began with a sodium zeolite followed by gradual increase of calcium and finally with formation of calcium zeolite or sometimes with silica. Some similarities exist between sequence of formation of zeolites in Davazdah Emam and Robat–Karim. Si/Al ratio of analcime in the study region is 1.99, indicating that hydrothermal origin. Consequently, analcime–paragenetic zeolites should also have formed hydrothermally.

Keywords:

Zeolite , Analcime , Hydrothermal , Davazdah Emam , Central Iran