Ultramarine analogs synthesized from cancrinite

The colored products analogous to ultramarine have been obtained by thermal treatment (500–800 °C) of cancrinite mixed with elemental sulfur and alkalis. The samples obtained at 500 °C maintain the original structure of cancrinite, while heating of the mixture at 800 °C resulted in zeolite structure transformation towards SOD in the case of mixture containing Na+ cations and to kaliophilite or unknown structures, when K+ or Li+ were applied as alkali sources. Encapsulation of sulfur species inside the cancrinite cages does not result in the generation of another radicals but S3-orS2-, which is reflected in the ESR spectra resembling those embedded in sodalite cages.