Aluminumsilicates

Aluminumsilicates are a broad group of silicate minerals and related compounds that contain aluminum and silicon within their crystal structures. In many aluminumsilicates, aluminum substitutes for silicon in the silicate tetrahedra, producing a framework of AlO4 and SiO4 units linked through shared oxygen atoms. This substitution introduces negative charges in the framework, which are balanced by exchangeable cations such as sodium, potassium, or calcium, and by water in hydrated forms.

Structural types include framework silicates (tectosilicates) such as feldspars and zeolites, and sheet silicates (phyllosilicates) such as clays and micas. Feldspars (plagioclase and alkali feldspars) are abundant minerals in the crust, while clays like kaolinite, illite, and montmorillonite are important soil components. Zeolites form porous frameworks with channels that adsorb molecules and exchange cations, making them valuable in catalysis and ion exchange.

Natural aluminumsilicates form through magmatic crystallization, metamorphic reactions, and weathering processes, and many synthetic aluminumsilicates are manufactured for industrial uses. Their properties—such as hardness, thermal stability, layered or porous structures, and cation-exchange capacity—determine their applications.

Applications include ceramics, glass and cement production, catalysis, adsorption and ion exchange, and soil amendment. The diversity of aluminumsilicates supports a wide range of technologies, from traditional ceramics to modern catalysts and environmental remediation.