engleski

Identification of some oxide minerals from Macedonia by powder XRD and FT IR spectroscopy

Continuing our research on the minerals from Macedonia [e.g. G. Jovanovski et al., N. Jb. Miner. Abh. 177 (2002) 241 ; B. Minceva-Sukarova et al., J. Mol. Struct. (2003), in press ; P. Makreski and G. Jovanovski, Bull. Chem. Technol. Macedonia, 22 (2003), in press] we have collected and identified several oxide minerals (hematite, Fe2O3 ; magnetite, Fe3O4 ; limonite, FeO(OH) ; corundum, Al2O3 ; rutile, TiO2 ; chromite, FeCr2O4) from various localities (Damjan, Ržanovo, Sivec, Veselčani, Pehčevo, Košino, Raduša). The powder XRD and the FTIR spectroscopy were used as a powerful, representative and relevant techniques for their successful identification. Namely, the identification was based on the comparison of their powder XRD patterns as well as the infrared bands (their number, frequencies and intensities) with the corresponding XRD [L. G. Berry and R. M. Thompson, X-ray Powder Data for Ore Minerals: The Peacock Atlas, New York, 1962] and FTIR literature data for the analogue natural and/or synthetic mineral species [e.g. M. Ocana and C. J. Serna, Spectrochim. Acta, 47A (1991) 765 ; M. Serna et al., Spectrochim. Acta, 38A (1982) 797 ; V. C. Farmer (Ed.), The Infrared Spectra of Minerals, London, 1974]. Some difficulties in the identification of studied minerals caused by the significant disagreement between the corresponding infrared spectra of the same mineral type found in the literature appeared. They were particularly expressed in the case of corundum and limonite [e.g. N. T. McDevitt and W. L. Baun, Spectrochim. Acta, 20 (1964) 799 ; I. I. Plyusnina, Infrakrasnye spektry mineralov, Moskva, 1977 ; I. Ya. Ryskin, The Infrared Spectra of Minerals, In V. C. Farmer (Ed.), London, 1974]. The identification was additionally complicated by the influence of the crystal form and particle size on the infrared spectra reproducibility. The difficulties were outrun mainly by use of the powder X-ray diffraction. Summarized discussion in that context will be given here.

minerals; FTIR spectroscopy; powder X-ray diffraction

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