Zeolite - Identifying Quality

First, I would like to provide some simple answers to basic questions about zeolite in general.

What is Zeolite-Clinoptilolite?
It is an aluminosilicate, a stone made of silicon and aluminum with many cavities (micropores). These are tiny "channels" with a diameter of 4-6 angstroms (0.4 - 0.6 nm). Due to its special grinding process, it has a very large specific surface area (both internal and external, including the micropores) and can absorb many pollutants such as heavy metals, ammonia, cadmium, etc., within these "channels." It contains silicon and other ions like calcium, potassium, sodium, and magnesium, all of which are negatively charged. There are many different types of zeolites, but only Clinoptilolite-zeolite has unique properties and is used as a feed additive only when it contains 80% or more clinoptilolite. The name "zeolite" comes from the Greek "zeo" meaning "to boil" and "lith" meaning "stone." The name was coined by the Swedish mineralogist Baron Axel Fredrick von Cronstedt, who noticed that when he applied a blowtorch to the stone, it began to boil due to the release of water contained within it. Bentonite-Montmorillonite, also an aluminosilicate, formed more slowly through the weathering of volcanic ash. Unlike zeolite, it is a layered silicate/clay silicate and therefore more challenging to mix with water. If simply stirred in, it clumps to the spoon like mud, needing time to swell or must be extremely finely mixed with zeolite to separate the individual bentonite particles, preventing them from sticking together. But anyone who has tried pottery is familiar with the characteristics of clay. :-)

How was Zeolite formed?
Millions of years ago, during volcanic eruptions, alkaline and alkaline earth metals, along with aluminosilicates, were expelled in the form of ash. This ash fell into saltwater, in the Carpathians at a time when the sea level was about 170 meters higher. This interaction between volcanic ash and sodium-rich seawater triggered a chemical reaction that eventually led to the formation of natural zeolite.

How does Zeolite work? What is its mechanism?
As a stone, it passes through the (mammalian) body only as a "guest" and is not metabolized. Due to its negative charge, it attracts positively charged heavy metals and pollutants like a magnet, binding them as it travels through the digestive tract until it leaves the body. In exchange for the absorbed toxins, it releases its calcium, potassium, sodium, magnesium ions, and its silicon ions in colloidal form into the body. This is why it is referred to as an ion exchanger. Additionally, its micropores, with their 4-6 angstrom diameter, are very well-suited for "docking" heavy metals.

What does Zeolite contain, and what is its composition?
Zeolite consists of silicon and aluminum, bonded in a framework, and the aluminum is not easily released, as is often claimed. In a technical sense, it functions at temperatures above 400°C, but doing so would completely destroy the framework structure. There are claims that grinding it to sizes smaller than 5, 10, or 20 micrometers releases aluminum from the framework, but this is not possible. The framework is a molecular structure that would need to be entirely destroyed, and this could only happen below the nanometer range. The micropores (channels) in zeolite have an average size of 0.4 to 0.6 nanometers and are enclosed by the framework. This size difference is like comparing a soccer ball to a speck of dust.

What about the lead in Zeolite?
Zeolite is a stone that is not metabolized and, like all aluminosilicates, contains heavy metals. A stone with an affinity for lead logically contains lead to some degree. It has absorbed it from its surroundings over thousands of years. The average lead content of the Earth's crust is 15 ppm (mg) of lead per kg, with agricultural soils naturally containing much more. A zeolite that can bind lead through Van der Waals forces cannot be completely lead-free unless it has been entirely isolated or has no affinity for lead at all. But in that case, it would not be effective for lead detoxification either. Cuban zeolite, for example, usually contains very little lead, but it has a higher affinity for copper, which is why it is often used for wastewater and soil remediation. However, it is not particularly known for absorbing large amounts of lead.

Regarding Zeolite-Clinoptilolite, I would like to address a common misconception that is frequently published. This is not an intake recommendation. Zeolite - Clinoptilolite is not a dietary supplement. It passes through the body as a guest, binding toxin ions to itself and, in exchange, releasing mineral ions in colloidal form to the body, which are metabolized, but not the zeolite itself.

If a food (supplement) containing 3 ppm lead/kg (maximum for dietary supplements) is ingested or fed, it is entirely bioavailable, and the body must somehow process those 3 ppm of lead. When zeolite-clinoptilolite is ingested or fed, the heavy metals present in the zeolite are bound by Van der Waals forces and can only be released by certain acids. This has been scientifically researched and confirmed in laboratory tests. When zeolite is tested for lead, this is done using aqua regia or microwave digestion. Aqua regia is a mixture of concentrated hydrochloric acid and concentrated nitric acid in a 3:1 ratio and is considered one of the strongest acids available.

In a laboratory analysis of zeolite, a lead content of 9.7 mg of lead per kg was found. In my opinion, this is a good value on the lower end. However, if you use an acid with a pH of 1.5, which corresponds to the stomach acid of non-vegetarian mammals, the bioavailability values differ significantly. Using 5g of zeolite in 1 liter of this artificial stomach acid at 40°C for 30 minutes results in a value of 0.008 ppm, which translates to 1.6 mg of lead per kg of zeolite as bioavailable in the stomach. And this is not for a food or dietary supplement, but for a stone and ion exchanger that does not easily release heavy metals. Additionally, it can absorb significantly more lead in the duodenum at a pH of around 8.2 than the amount released into stomach acid. Its cation exchange capacity is determined, including the contained lead. Zeolite - Clinoptilolite unfolds its adsorption power in the alkaline environment of the intestines. This is the unique property of Zeolite - Clinoptilolite, in stark contrast to activated charcoal, which releases everything once it is saturated.

However, I have also seen suppliers who seem to suggest that aluminosilicates contain no heavy metals at all. Statements like "Independently tested in laboratories, therefore free of pollutants" are pure nonsense. A test does not change the heavy metal content, but what won’t people do for marketing. :-))

For your information:
Maximum total heavy metal content for medical-grade Zeolite Class I, IIa/IIb: 50ppm/kg
Maximum lead content for Zeolite as an animal feed additive: 60 ppm/kg

The Data Sheet
The data sheet should contain all relevant information, not just the mineralogical composition. Professor Hecht always insisted that it should include data like the selectivity series, grain size, clinoptilolite content, silicon-aluminum ratio, cation exchange capacity (CEC), heavy metals, and if possible, occasional in-depth analysis of the quarry. These are not all continuous investigations, but heavy metals should be tested in every batch.

Zeolite Quality
After some of the slightly hysterical discussions online about what supposedly makes a good zeolite, let’s take a calmer approach. Instead of relying on unverifiable claims of "best quality, finely ground" or "the grinding degree must not fall below 100 microns, or nanoparticles will form!!", let’s take a closer look at what really matters for quality. You don’t have to be an expert to understand the essential aspects.

A simple example: When you buy a high-quality wall paint, you also make sure that a single bucket of this paint covers 100 m² and not just 15-20 m². That would not only be expensive but also exhausting.

Fortunately, there is a specific value that clearly shows how much "power" a zeolite has, and that is the cation exchange capacity (CEC). It indicates how many cations the zeolite can absorb. Since cations are positively charged, like various toxins and heavy metals, the higher the CEC, the greater the absorption capacity. A high CEC is always associated with fine grinding and effective activation, whether through air-stream grinding or thermal activation. The specific surface area is also closely linked to this. For instance, a finer zeolite is very light, so one kilogram of a 6 μm material has a volume of 2 liters. You might pay more per kilogram compared to coarser material, but you get more in terms of volume.

An example as a reference point: Identical zeolite, treated the same way but with different grinding and activation processes, results in 20 µm zeolite absorbing 1 mg of heavy metals per gram, while the 6 µm zeolite absorbs 2 mg of heavy metals per gram. With the right activation process and, if necessary, additional triboelectric charge to enhance adsorption forces, the capacity can be even higher.

Some people are now talking about micro or nano-sized zeolites. In reality, this is nonsense. "Nano" means extremely small, while "micro" means somewhat larger. A nanometer is one-billionth of a meter, while a micrometer is one-millionth of a meter. It's difficult to imagine something this small, so let's make it more tangible: The micropores in zeolite have an average size of 0.4 - 0.6 nanometers, meaning they are 500 to 1,500 times smaller than a micron-sized zeolite. This means that nanozeolite could theoretically penetrate this grid. A grain size below 5 microns would require the micropores to be completely destroyed, which would also destroy the clinoptilolite framework and turn the stone into amorphous silica. But that would be the end of it.

In conclusion, always pay attention to these values: the cation exchange capacity (CEC) and the specific surface area. If a zeolite has not been tested for these values, it is better to look for another source. And don’t be misled by sales slogans like "best quality, finely ground" or "free of pollutants".