Raman and infrares spectra of carbonates of calcite structure

The Raman and mid-range infrared spectra have been measured on natural limestone and dolomite minerals. The carbonate minerals show four prominent absorption bands in the regions 1450-1420, 890-870, 720-700 and 1000-1100 cm(-1). The positions of the wavenumbers are unique for each carbonate mineral and are thus diagnostic of their mineralogy. Calcite and dolomite groups are characterized by the Raman wavenumbers at 288 and 309 cm(-1) and the infrared absorption bands at 712 and 728 cm(-1), respectively. The principal wavenumber at 1092 cm(-1) in the limestone spectra is accompanied by two satellites with values of 1062 and 1075 cm(-1). The observed non-split peaks nu(2) and nu(4) in the infrared spectra of limestone indicate the presence of calcite structure in all these samples. The principal reflections occurring at the d-spacings, 3.03482, 1.91658 and 1.87962 angstrom, confirm the presence of calcite structure in limestone minerals. The principal reflections occurring at the d-spacings, 3.037, 1.79179 and 2.19750 angstrom, confirm the existence of dolomite structure in the dolomite minerals. The calculated lattice parameters for the limestone minerals are: a = 4.9781 angstrom, c = 17.1188 angstrom and V = 367.392(angstrom)(3) and the corresponding values for the dolomite minerals are: a = 4.8247 angstrom, c = 15.9868 angstrom and V = 322.28 (angstrom)(3). Copyright (c) 2006 John Wiley & Sons, Ltd.