BÖTTCHER, M.E., GEHLKEN, P.-L. & USDOWSKI, E. & REPPKE, V. (1993):
An infrared spectroscopic study of natural and synthetic carbonates from the quaternary system CaCO3-MgCO3-FeCO3-MnCO3.
Infrared spectroscopic measurements have been carried out on natural and synthetic rhombohedral carbonate samples from the quaternary system CaCO3 – MgCO3 – FeCO3 – MnCO3, including the complete dolomite-ankerite mineral series, synthetic siderite, calcium-siderite and iron-calcite. Significant frequency shifts in the 2 and 4 vibrational bands of the carbonate ion group occur as a function of cationic substitution. Based on pure end-member data, 2 – 4-diagrams are constructed reflecting chemical compositions in the ternary systems CaCO3 – MgCO3 – FeCO3 and CaCO3 – MgCO3 – MnCO3. In a rigorous quantitative evaluation of infrared frequencies of carbonate minerals from the quaternary system the complete chemical compositions have to be considered, because the 2 and 4 wave-number positions of calcite, magnesite, siderite and rhodochrosite differ significantly from each others.