SiAl4O10OH2

SiAl4O10OH2 is a chemical formula describing a hydrous aluminosilicate composition containing silicon, aluminum, oxygen, and hydroxyl groups. The ratio implies one silicon atom for every four aluminum atoms in a tetrahedral framework, with hydroxyl groups incorporated into the structure. In such a framework, aluminum would substitute for silicon in TO4 tetrahedra, introducing negative framework charge that is typically balanced by protons or extra-framework species; the hydroxyl groups indicate a hydrated or partially dehydroxylated state.

In mineralogical terms, the exact empirical formula SiAl4O10OH2 does not correspond to a widely recognized named species in major databases. It is more commonly encountered as a theoretical or model composition used to describe highly aluminous aluminosilicate frameworks, or as a component of synthetic or amorphous/hydrated materials rather than a well-ordered mineral. As such, any natural sample with this precise stoichiometry, if it exists, would likely occur as a poorly crystalline, glassy, or gel-like phase, or as part of a solid-solution series in synthetic aluminosilicates.

Relation to broader groups includes aluminosilicates such as clays, zeolites, and framework silicates, where varying Al content and the presence of hydroxyl groups influence structure and properties. SiAl4O10OH2 serves primarily as a descriptive formula for discussing aluminum-rich, hydroxyl-bearing aluminosilicate frameworks rather than as the name of a distinct mineral species.

See also: aluminosilicate, zeolite, clay minerals, imogolite, allophane.