Nine samples of carbonate-free sodalite-group minerals, including those with abnormally high contents of polysulfide groups, fluoride anion and carbon dioxide molecules as well as synthetic fluoraluminate sodalite-type compound Na₈(Si₇Al₅O₂₄)(AlF₆)^3–·5H₂O, have been studied by means of electron microprobe analyses, infrared and Raman spectroscopy; the CO₂ content was determined using the selective sorption of gaseous ignition products. This article describes a semi-quantitative method for estimating the content of carbon dioxide molecules in these minerals, based on IR spectroscopy data. The data obtained demonstrate the existence of a sulfide sodalite-group mineral with the idealized formula Na₇(Si₆Al₆O₂₄)(S₃⁻)·H₂O, which differs significantly from the formula Na₆Ca₂(Si₆Al₆O₂₄)S^2–₂ accepted for lazurite. According to single-crystal X-ray structural analysis, in the F-rich sodalite-group mineral from the Eifel paleovolcanic region, Germany with the idealized formula Na₇(Si₆Al₆O₂₄)F⁻·nH₂O fluorine occurs as an isolated F⁻ anion, unlike synthetic F-rich sodalite-type compounds.