NaK23Al3AlSi2Si13O361416H2O

NaK23Al3AlSi2Si13O36·14H2O is a hydrated aluminosilicate with a three-dimensional framework of corner-sharing TO4 tetrahedra (T = Si, Al). The structure hosts mixed alkali cations, primarily Na+ and K+, that balance the framework’s negative charge. Water molecules occupy channels and cages within the framework, with hydration levels that vary with temperature and humidity.

Composition and structure: Silicon and aluminum occupy tetrahedral sites in a proportion that yields a net negative framework charge, balanced by extra-framework Na+ and K+. The exact distribution of Si and Al and the degree of hydration influence pore geometry, cation positions, and stability. The material exhibits zeolite-like features, including porosity and ion-exchange capacity.

Synthesis and occurrence: The compound has been described in the literature as a synthetic phase obtained under alkaline hydrothermal or solvothermal conditions. It forms crystals that can be needle- or plate-like; there is no widely documented natural mineral with this exact composition.

Properties and applications: Depending on hydration, crystals are colorless to white with a non-metallic luster. They are typically soft for silicate frameworks, display notable porosity, and show ion-exchange capabilities. Potential uses include adsorption, separation, and catalyst support, with performance tunable by alkali content and hydration.

The name reflects the constituent elements—Na and K as alkali cations; Al and Si in the framework; oxygen; and water of hydration.