What is zeolite?

Zeolites are microporous crystalline aluminosilicates that result from the interaction of volcanic rocks, ash deposits, and alkaline groundwater. The Atlas of Zeolite Framework Types has documented approximately 218 distinct zeolite structures, with around 40 classified as natural zeolites. These natural zeolites are recognized by the U.S. Food and Drug Administration for human consumption (FDA GRAS Listings, 2006) and have been deemed non-toxic by the World Health Organization’s International Agency for Research on Cancer (IARC, 1997). Additionally, the Codex Alimentarius Commission (1999) includes certain zeolites as approved substances for use in Organic Food Production and Plant Protection.

Many of us are familiar with the zeolites used in water softener systems. The zeolite core in these systems effectively absorbs significant amounts of metals such as calcium and magnesium from water. To maintain its effectiveness, the zeolite is periodically flushed with a concentrated saltwater solution, which removes the metal ions and rejuvenates the zeolite for future absorption. The most commonly used types of zeolites in water softeners include natural aluminosilicates, gluconites (commonly known as greensand), and synthetic permutite.