What is Zeolite?
The zeolite group is a family of hydrated framework silicates with open channels that exchange water and cations. It is a major collector category and a foundation of natural mineral filtration science.
Mineralogy and structure
Reference formula: M(AlO2)x(SiO2)y·nH2O. Zeolite is the existing canonical Guide record for the zeolite group, not a single mineral species. Zeolites have variable chemistry and symmetry, so no single lattice or universal formula should be presented as the structure of the whole group. Zeolite is classified with silicates and has variable or not assigned for this reference crystal symmetry. Typical hardness is 3.5–5.5 on the Mohs scale and specific gravity is approximately 2.0–2.4.
Colour, lustre and habit
Typical colours include colourless, white, pink, green, brown. The usual fibrous, tabular, prismatic habit and vitreous, pearly, dull lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Zeolite forms in or is associated with volcanic cavities, hydrothermal veins, sedimentary diagenesis and low-temperature alteration. Important documented localities include India, Iceland, Italy, Scotland, Georgia, the United States and Japan.
A whole family of porous crystal frameworks
Zeolite specimens sell through texture and story: sparkling stilbite, radiating natrolite and dramatic basalt cavities turn an open framework into a display piece with real industrial relevance.
Collecting and care
Many zeolites are delicate and hydrated: avoid soaking, heat and strong acids. Keep fibrous material enclosed, and identify the species before selling or using it for technical purposes.
