The usual methods of quantitative analysis in general do not allow to establish the phase composition of the mixture. Knowledge of the phase composition of carbonate rocks in a number of cases is of interest in geological surveys, technological processes of processing of these rocks, etc. So, for example, for a mixture of carbonate rocks quantitative analysis gives only the total content of calcium and magnesium, and to establish by this method the number of individual phases (calcite, dolomite and magnesite) in their combined presence is not possible.