Electron Microprobe and Raman Spectroscopy Investigation of an Oxygen-Bearing Pt-Fe-Pd-Ni-Cu Compound from Nurali Chromitite (Southern Urals, Russia).
One grain, about 100×80 μm in size, occurring in chromitite associated with the layered sequence of the Nurali mafic-ultramafic complex (Southern Urals, Russia) was investigated by electron-microprobe analyses and Raman spectroscopy. The grain is characterized by a spotty, rugged appearance and chemical zoning from which two compositions were calculated: (Pt(0.35)Pd(0.26)Fe(0.22)Cu(0.01)Ni(0.05))(0.98)O(1.02) and (Fe(0.90)Pt(0.58)Ni(0.28)Pd(0.13)Cu(0.08)Rh(0.01))(1.98)O(1.02). In the lack of X-ray data, Raman spectroscopy established the presence of a diffuse 500-700 band and a sharp peak at 657 cm⁻¹ of relative wavenumber that strongly resemble the Raman spectra of synthetic PtO and PdO (palladinite). It is concluded that the Nurali grain probably represents a platinum group element (PGE) oxide, and does not consist of a mixture of PGE alloys with Fe oxide or hydroxide as reported for other natural PGE-O compounds.
1Department of Applied Geosciences and Geophysics,University of Leoben,A 8700 Leoben,Austria.
Federica
F
Zaccarini
1Department of Applied Geosciences and Geophysics,University of Leoben,A 8700 Leoben,Austria.
Giorgio
G
Garuti
1Department of Applied Geosciences and Geophysics,University of Leoben,A 8700 Leoben,Austria.
Ronald J
RJ
Bakker
2Ural Division of Russian Academy of Sciences,Institute of Geology and Geochemistry,Str. Pochtovy per. 7,620151 Ekaterinburg,Russia.
Evgeny
E
Pushkarev
PGE oxides; Raman spectroscopy; Russia; chromitite; electron microprobe