After an examination of the chemical analyses of chabazites reported in literature, 28 samples have been selected for detailed study. The chemical analyses, unit-cell dimensions, refractive indices and densities of these samples are given. The X-ray diffraction powder patterns, I)1A curves and a description of the behavior on heating of three samples are reported. The correlations between chemical and physical properties are determined. Equations for estimating the Si/(Si+Al+Fe) ratio and the sum of exchangeable cations from the measured values of a and c are calculated, as well as the ratio between the sum of monovalent cations and the sum of all exchangeable cations from the measured value of ω. The results of the chemical analyses exclude the presence of a compositional gap between Ca and Na end-members.