Systematics, crystal structures, and occurrences of zeolites

Zeolites represent the mineral supergroup with the highest number of different structure types. Their highly characteristic features (e.g., reversible low-temperature dehydration, ability of the dehydrated forms to adsorb polar molecules, low-temperature cation exchange capacity) are governed by the microporous nature of zeolites. In this chapter, we provide an overview on systematics, crystal structures, and occurrences of natural zeolites. In response to the structural complexity and diversity of natural zeolites, we follow the classification scheme previously adopted by Gottardi and Galli (1985) and Armbruster and Gunter (2001), dividing zeolites into six different subgroups.