aluminiumsilikater

Aluminiumsilikater, commonly called aluminosilicates, are minerals and synthetic materials based on aluminum, silicon, and oxygen. Their core feature is a three‑dimensional network of silicon‑oxygen and aluminum‑oxygen tetrahedra (SiO4 and AlO4) linked by shared oxygen atoms. Replacement of silicon by aluminum within the framework introduces negative charge, which is balanced by interstitial cations such as sodium, potassium, calcium, or others. This gives rise to a range of chemical compositions and physical properties.

Structurally, aluminosilicates are classified according to how the tetrahedra connect. Tectosilicates (framework silicates) have each tetrahedron sharing all four oxygen corners; phyllosilicates (sheet silicates) have layered structures; zeolites are porous framework silicates with channels that house cations and water. Natural examples include feldspars (end‑members orthoclase KAlSi3O8 and albite NaAlSi3O8; plagioclase series CaAl2Si2O8–NaAlSi3O8), micas such as muscovite KAl2(AlSi3O10)(OH)2, and clays like kaolinite Al2Si2O5(OH)4. Zeolites, such as analcime and natrolite, are hydrated framework alumin silicates with well‑defined pore systems.

Aluminosilicates occur widely in nature, formed through crystallization from silicate melts, hydrothermal processes, or weathering and alteration of existing rocks. They have broad industrial importance: feldspars provide raw material for ceramics and glass; clays are used in ceramics, paper, and binders; zeolites and related materials serve as catalysts and ion‑exchange media, adsorbents, and refractory supports.