When rapidly heated, stones containing Zeolites are observed to release water and appear to boil. The name "zeolite" which is derived from the Greek words Zeo and Lithos reflects this property as it translates as "stone that boils".
Naturally occurring zeolites are rarely pure and are therefore often unsuitable for practical applications. On the other hand many zeolites that are interesting with respect to their properties are rarely found in nature. For these reasons a huge number of synthetic zeolites have been engineered over a period of more than half a century. Synthetic Zeolites, often also called molecular sieves, are used in a wide range of applications including detergents, catalysts and adsorbents.