14 Mar Natural and Synthetic Zeolites
1.) Definition
The name “zeolite” goes back to the Swede Axel Fredrick von Cronstedt, who created this name in 1756 which means “boiling stone” (the Greek word “zeos” means “boiling” and the word “lithos” means “stone”).
Zeolites are hydrated alumosilicates of the alkaline and alkaline-earth metals [1].
2.) About zeolites
Zeolites are tectosilicates: The crystal lattice of tectosilicates consist of an infinite 3D-framework of SiO4-tetrahedra. Zeolites are able to adsorb water and exchangeable cations within their interspaces and can replace these cations. The substitution of Si4+ to Al3+ causes charging deficiencies and therefore negative charges of the lattice and surface [2, 3].
There are about 40 different natural zeolites identified such as clinoptilolite, heulandite, analcime, chabazite, laumonite, mordenite and phillipsite. More than 150 zeolites-types have been synthesized. For example Zeolites A, X, Y and ZMS-5.
Both (natural and synthetic) zeolites are used for adsorption, ion-exchange, molecular sieve, and catalytic properties [1]. There are many uses for zeolites, from industrial to medical, for example filtration of waste water – removing heavy metal ions, or radioactive isotopes, soil remediation in agriculture, maintaining and supporting healthy aquaculture (fish farming) and also as a multi-functional and beneficial livestock feed additive
[1]. For human applications (pharmaceutical and alternative medicine) it is necessary to use only high-grade clinoptilolite/ zeolite minerals, which were purified under quality-controlled conditions meeting regulatory standards; especially for daily oral consumption, the clinoptilolite dietary supplement has to be 100% safe [2].
3.) Exploitation
Natural zeolites are mined in different deposits all over the world, for example in Slovakia (Europe), in the USA (e.g. Nevada, Idaho, Oregon), in Kuba, in Turkey, and many other countries. They are mainly of volcanic origin having various raw-material qualities [1, 3, 4]. The natural zeolite from eastern Slovakia fulfills the highest quality standards and is of unsurpassed homogeneity and purity.
Synthetic zeolites are produced by using natural raw materials and/or synthetic silicate that experience imitate hydrothermal processes using elevated temperature or pressure [4]. The advantage of synthetic zeolites is that they can be produced having the exact (mostly large) pore-sizes, needed for specific applications; the advantage of natural zeolites is that they are very stable in low pH environments (as found in the stomach) and in changing pH environments (like present in the GI-tract).
G-PUR® Purified Clinoptilolite is naturally sourced in Slovakia and purified in Austria.
References:
[1] Robert L. Virta, Zeolites. In: U.S. GEOLOGICAL SURVEY MINERALS YEARBOOK—1999
[2] Mona M. Haemmerle, Joachim Fendrych, Elisabeth Matiasek and Cornelius Tschegg, Adsorption and Release Characteristics of Purified and Non-Purified Clinoptilolite Tuffs towards Health-Relevant Heavy Metals In: Crystals 2021, 11, 1343. https://doi.org/10.3390/cryst11111343
[3] Cornelius Tschegg, A. Hugh N. Rice, Bernhard Grasemann, Elisabeth Matiasek, Pavel Kobulej, Martin Dzivák, and Thomas Berger (2019): Petrogenesis of a Large-Scale Miocene Zeolite Tuff in the Eastern Slovak Republic: The Nižný Hrabovec Open-Pit Clinoptilolite Mine. Economic Geology
[4] Magdalena Król, Natural vs. Synthetic Zeolites, In: Crystals 2020, 10(7), 622; https://doi.org/10.3390/cryst10070622
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