Permingeatite, Cu3SbSe4, from Příbram (Czech Republic): description and Raman spectroscopy investigations of the luzonite-subgroup of minerals
Abstrakt
Permingeatite from the Příbram uranium-base metal ore district (central Bohemia, Czech Republic), has been studied in detail. Based on electron microprobe analysis, the empirical formula of the studied permingeatite (mean of 10 point analyses, based on Sb+Cu+Fe+Se+S=8 apfu) is Cu3.00(Sb0.99Fe0.04)Σ1.03(Se3.74S0.23)Σ3.97.
The unit-cell parameters refined from powder X-ray diffraction data are a=5.6323(2) Å, c=11.2354(7) Å, with V=356.41(2) Å3 (for space group I42m). The Se-S substitution is characteristic for this permingeatite.
The only other element which enters the structure of the luzonite-group minerals in considerable concentrations is Fe. The dominant feature in the Raman spectra of the studied minerals is a suite of spectral bands that corresponds to the stretching and bending vibrations of tetrahedral XY4 (X = As/Sb; Y = S/Se) groups.