What is Zeolite?
Basically it is micro-porous minerals of volcanic origin. Zeolite is an inorganic porous material having a highly regular structure of pores, chambers or capillaries that are naturally negatively charged that allows some molecules to pass through, and causes others to be trapped inside its chambers. The only zeolite suitable for humans and animals is clinoptilolite or sodium aluminosilicate.

Background - or Rediscovery of Zeolite
After the knowledge of zeolite was lost to mankind with the demise of the Roman empire, zeolites were rediscovered and described in 1756 by Cronstedt, a Swedish mineralogist who coined the name from two Greek words meaning 'boiling stones', referring to the evolution of steam when the rock is heated. About fifty different natural zeolites are now known and more than one hundred and fifty have been synthesized for specific applications such as industrial catalysis or as detergent builders.

Clinoptilolite is a naturally occurring zeolite, formed by the devitrification (ie the conversion of glassy material to crystalline material) of volcanic ash in lake and marine waters millions of years ago. It is the most researched of all zeolites and is widely regarded as the most useful. In common with other zeolites, clinoptilolite has a cage-like structure consisting of SiO4 and AlO4 tetrahedra joined by shared oxygen atoms. The negative charges of the AlO4 units are balanced by the presence of exchangeable cations - notably sodium, calcium, magnesium, potassium and iron.

These ions can be readily displaced by other substances, for example heavy metals (mercury, lead, cadmium, etc..) and ammonium ions. This phenomenon is known as cationic exchange, and it is the very high cationic exchange capacity of clinoptilolite which provides many of its useful properties. Being a naturally occurring mineral, the precise composition of clinoptilolite is subject to a degree of variation. However, an approximate empirical formula is (Na, Ca, Fe, K,)3-6Si30Al6O72.24H2O. The Chemical Abstracts Service (CAS) Number for clinoptilolite is 12173-10-3.