silicatealuminate

Silicatealuminate is an informal term for compounds and materials that contain silicate and aluminate units in their structure. It is most commonly used to refer to aluminosilicates, a large and diverse family based on silicon, aluminum and oxygen, typically with charge-balancing cations such as sodium, potassium or calcium.

In these materials, aluminum substitutes for a portion of silicon in tetrahedral sites, creating a framework with a negative charge that is balanced by extra-framework cations. The silicate and aluminate units link to form three-dimensional networks in tectosilicates or two-dimensional sheets in phyllosilicates; some frameworks also create porous structures in zeolites.

Natural examples include feldspars (potassium feldspar KAlSi3O8, albite NaAlSi3O8, anorthite CaAl2Si2O8), and clays such as montmorillonite. Mullite, with the composition 3Al2O3·2SiO2, is a high-temperature aluminosilicate used in ceramics and refractories. Zeolites are porous aluminosilicates used as catalysts, ion exchangers and adsorbents.

Applications span geology, ceramics, cement chemistry (calcium aluminosilicate hydrates), refractories and catalysis, with properties including hardness, chemical stability and thermal resistance, as well as framework porosity in zeolites that enables selective adsorption and ion exchange.

Terminology note: aluminosilicate is the standard term in mineralogy and materials science; silicatealuminate is a descriptive, less common variant.