The Zeolite group of minerals is an important mineral group for industrial purposes and many others. It is also the most popular mineral group for most mineral collectors. What makes it popular is the combination of its complexity, beauty, and unique crystal habits. The structure of zeolites are framework of silicates tetrahedrons interlocking each other. It has been known that the alumino-silicate structure is negatively charged and it readily attracts the positive cations that reside within. Unlike most other tectosilicates, zeolites have large vacant spaces or cages in their structures that allow space for large cations such as sodium, potassium, calcium, barium and even relatively large molecules and cation groups such as water, ammonia, carbonate ions and nitrate ions. It has been known that in the most useful zeolites, the spaces are interconnected and form long wide channels of varying sizes depending on the mineral. These channels allow the easy movement of the resident ions and molecules into and out of the structure. Zeolites are characterized by their ability to lose and absorb water without damage to their crystal structures. The large channels explain the consistent low specific gravity of these minerals.  

 

Zeolites typically form in the cavities or vesicles of volcanic rocks. Zeolites as studied in the field of optical mineralogy are the result of the very low grade metamorphism. Some of them form from just subtle amounts of heat and pressure. It has been known in the field of optical mineralogy that it can actually just barely be called metamorphic while others are found in obviously metamorphic regimes. Zeolite crystals have been grown on board the space shuttle and are undergoing extensive research into their formation and unique properties.

 

            Zeolites have many useful purposes. Zeolites are known to have the capacity to perform ion exchange, odor removal, filtering, chemical sieve and gas absorption tasks. The most well known use for zeolites is in water softeners. Calcium in water can cause it to be hard and can make it capable of forming scum and other problems. It has been known in some scientific studies that zeolites charged with the much less damaging sodium ions can allow the hard water to pass through its structure and eventually exchange the calcium ions for sodium ions. This process is reversible. In similar way, zeolites can absorb ions and molecules and thus act as a filter for odor control, toxin removal and as a chemical sieve. In optical mineralogy, it has been known that zeolites can have the water in their structures driven off by heat with the basic structure left intact. Then other solutions can be pushed through the structure. The zeolites can then act as a delivery system for the new fluid. It has been found that this process has applications in livestock feeds, medicines, and other types of research. Zeolites added to livestocks feed have been found or shown to absorb toxins that are damaging and even fatal to the growth of the animals, while the basic structure of the zeolite is biologically neutral. Since zeolites also make excellent removers of ammonia and other toxins, it can be found used by many aquarium hobbyist who see more zeolite products in pet stores. It has been known that most municipal water supplies are processed through zeolites before public consumption. These uses of zeolites are extremely important for industry, although synthetic zeolites are now doing the bulk of the work.  

 

            It has been known in the field of optical mineralogy, zeolites have basically three different structural variations. These are chain-like structures that includes those minerals form acicular or needle-like prismatic crystals; the sheet-like structures that includes minerals with crystals that are found flattened platy or tabular with usually good basal cleavages when viewed with the aid of petrographic polarizing light microscopes; and the framework structure that includes minerals with crystals that are more equant in dimensions. Zeolite they say can be though of in terms of a house are really very likely to that of a zeolite. The chain-like structures can be thought of like a tower or high wire pylons. The sheet-like structures can be thought of like large office buildings with the sheets analogous to the floors and very few walls between the floors. The framework structures like houses with equally solid walls and floors. All these structures are still frameworks.