St. Cloud Zeolite | Winston, NM | Ash Meadows, NV | Bowie, AZ

Contact Us


St. Cloud Zeolite
T: (203) 364-0600
F: (203) 364-1959


St. Cloud Mining Co.
T: (575) 743-5215
F: (575) 743-3333

Mailing Address

St. Cloud Mining Co.
PO Box 196
Winston, New Mexico 87943

Physical Address

Winston Millsite
Winston, New Mexico 87943

zeolite text zeolite

All zeolites are not created equal. Characterized by its high surface charge density and high cation exchange capacity, St. Cloud Zeolite’s unique ability to absorb and bind a broad range of materials makes it a simple and inexpensive solution to many problems spanning a variety of industries.

St. Cloud Zeolite

“St. Cloud’s zeolite is notable for its responsiveness, consistency, attrition resistance, pH buffering characteristics, moisture retention, attractive color, compatibility with other nutrients and additives, product availability, quality control, manufacturing capacity and price.”

– U.S. Geological Survey 96-065

Whether in NASA labs or at concentrated animal feeding operations (CAFO’s), St. Cloud Zeolite delivers measurable results that improve performance while lowering costs.

St. Cloud Zeolite - Uniquely Valuable

Like other natural zeolites, St. Cloud Zeolite consists of a negatively charged three-dimensional aluminosilicate lattice which forms a vast network of open channels and internal surface area. Loosely bound, positively charged atoms called cations are attached to the lattice structure by an electrical bond.

Many natural zeolites contain sodium (Na+) as the primary exchangeable cation which can have a deleterious impact upon numerous organic and industrial processes. With calcium (Ca2+) as its primary cation, St. Cloud Zeolite is the preferred zeolite for a large array of applications requiring highly effective overall cation exchange capacity with minimal sodium release.

The capacity of a natural zeolite to exchange and load cations is a function of its chemistry, bulk density, exchangeable cations and charge density. Zeolites from different geological deposits may look alike and may even have very similar chemical analyses. But there are other naturally occurring properties, not often reported or infrequently measured, that distinguish one zeolite from another and have considerable impact on their effectiveness in particular applications.

Zeolites and Surface Charge Density

A significant and often overlooked property is surface charge density. The charge density of any zeolite is a function of the number of cation exchange sites per unit area of zeolite and the reactivity of the zeolite surface. The charge density and cation exchange capacity characteristics can vary between the internal surfaces of the zeolite (which are accessible only to small ions and molecules) and the external surfaces of the zeolite (which are accessible to most chemicals regardless of size).

A high surface charge density means there are more cation exchange sites on the external surface of the zeolite lattice. The more numerous and readily available the sites, the faster the exchange can occur.

When compared to other zeolites, St. Cloud Zeolite has been shown to have a surface charge density of at least twice that of other natural zeolites measured. Its surface charge density properties make St. Cloud Zeolite particularly valuable in applications where the cation exchange process must be maximized without extended exposure.

Scientific measures are only a part of the story. The real testimonial to the effectiveness of St. Cloud Zeolite is its widespread acceptance in water, chemical treatment, and animal feed applications. Whether you need the benefits of high surface charge density or a long lasting filtration media, St. Cloud Zeolite has proven itself to be among the most versatile and effective produced today.

Certified Clay Free

The volcanic minerals that became the St. Cloud Zeolite deposit settled on top of the highly active geothermal region of what is now southwest New Mexico. As overburden covered the deposit, geothermal activity baked and leached the clays and other feldspars from the stable aluminosilicates, resulting in the clean, high quality zeolite produced at St. Cloud today. As a result of the natural geological process, St. Cloud Zeolite contains virtually no soluble clays and is among the most abrasion resistant (hardest) zeolite on the market.

Other zeolites may contain clay in such quantities as to adversely affect permeability or may contain materials such as asbestos related fibrous silicates that can impair product performance and cause health or environmental hazards. X-ray diffraction and electron microscope scans have consistently shown that St. Cloud Zeolite is a high-grade clinoptilolite product with no fibrous silicates.

Other zeolites may consist of low  silica to alumina ratios which could contribute to a premature degradation of the overall zeolite structure in even mildly acid environments. With a silica to alumina ratio of 5 to 1, St. Cloud Zeolite is among the most stable and multipurpose natural zeolite available.

St. Cloud vs. Other US Zeolites

In a report* comparing St. Cloud Zeolite to some other U.S. zeolites, the United States Geological Survey (USGS) found St. Cloud had:

Better Performance

Studies by the University of Florida, Rutgers, Texas A & M and other institutions found that St. Cloud Zeolite performs better than other commercially available soil additives.

  • lowest Na+ content and exchangeability
  • highest Ca2+ content and exchangeability
  • highest capacity to adsorb K+
  • best pH stability and neutralizing effect
  • highest loading capacity of combined N+-K+-Ca2+ in contact with fertilizers of producing properties
  • average total N capacity and most readily available N

(* Desborough, G.A., 1996 Clinoptilolite-rich Rocks in Agricultural Use for Soil Amendment and Potential Nitrogen-pollution Migration. USDI, US Geological Survey, Open-file Report 96-065, 32 p.)

Comparing Zeolites

When comparing zeolites, be sure to evaluate such critical properties as:

  • surface charge density
  • cation exchange capacity
  • selective adsorption of cations
  • permeability
  • surface area
  • pH buffering
  • reversible hydration and dehydration
  • high ability to absorb gases
  • high thermo-stability
  • resistance to abrasion and breakdown

When you evaluate the differences, you’ll find St. Cloud Zeolite possesses superior measures of the key performance indicators that will make the difference you’re looking for. See our Specifications Sheet for a comprehensive listing.