Minerals from Macedonia IV.Discrimination between some carbonate minerals by FTIR spectroscopy

The use of FTIR spectroscopy to distinguish between some geologically im­portant carbonate minerals (calcite - CaCO3), aragonite - CaCO3, siderite - FeCO3, magnesite - MgCO3, and dolomite - CaMg(CO3)2 originating from Macedonia and to detect mineral impurities in them is considered. 1t was shown that the series of the studied isomorphous calcite type minerals is an ideal test case for the evaluating the in­fluence of the corresponding cation upon the band frequencies or the carbonate v3, V2 and v4 modes in their infrared spectra. It enables to distinguish the isomorphous calcite type carbonates from one another. In the course of the quantitative determination of the composition of mixtures it is shown that the limit of detection of impurities of ara­gonite in the mixtures with calcite (or other calcite type minerals) is around I wt %. The spectra or natural calcite and siderite were compared to those of their synthetic analogues