Minerals from Macedonia XIV. Identification of some sulfate minerals by vibrational (infrared and Raman) spectroscopy

The following six sulfate minerals: anhydrite, CaSO4; brochantite, Cu-4(SO4)(OH)(6); jarosite, KFe3(SO4)(2)(OH)(6); potassium alum, KAl(SO4)(2).12H(2)O; chalcanthite, CuSO(4)(.)5H(2)O and epsomite, MgSO(4)(.)7H(2)O collected from different localities of Macedonia (Debar, Alsar, Bucim, Bukovik), are studied and identified using Fourier transform infrared (FTIR) and Raman spectroscopy. The difficulties related to the contamination, identification and characterization of the mentioned minerals are discussed. The identification is based on the concept of group frequencies interpretation of the bands due to the main SO4 vibrational units, additionally supported by the assignment of the OH or H2O group vibrations present in all samples, except anhydrite. The results obtained by use of the vibrational (infrared and Raman) spectroscopy are compared with the corresponding literature data for the analogous mineral species (originating all over the world) or their synthetic analogues, as well. (c) 2005 Elsevier B.V. All rights reserved.