A series of high-entropy sodalite-and cancrinite-type feldspathoids with mixed Cl–, Br–, I–, S4, S2O32–, Na+, K+ and Ca2+ extra-framework species were synthesized under soft hydrothermal conditions, in order to evaluate the influence of heteroatomic substitutions on luminescence properties and thermal stability of feldspathoids. It was found that relative stability of either cubic sodalite or the hexagonal cancrinite framework is strongly dependent on the type of anionic species. The partial substitution of (Na, K) for Ca, along with the mixed halogen occupancy, substantially improves the thermal stability of sodalites. Novel data on intrinsic luminescence attributed to recombination of electron and hole on halogen-metal complexes within cages is presented. The intrinsic luminescence bands span the entire visible region and depend on the geometry of the cages. The excitation of the luminescence occurs at ∼5 eV (250 nm).
