Přibramite, a new Se-containing mineral from the Czech Republic, characterized by Raman spectroscopy

In the paper by Sejkora et al [1] several members of the CuSbS₂-CuSbSe₂ join were studied by micro–Raman spectroscopy:

• příbramite CuSbSe₂, which got its name from its bith place, Příbram (Czech Republic)
• chalcostibite CuSbS₂ from Dúbrava (Slovak Republic)
• Se-rich chalcostibite

The main internal and external vibrations of these compounds were identified and related to pyramidal Sb(S,Se)₃ groups, Cu-(S,Se) bonds and external lattice modes. The příbramite mineral only forms polycrystalline aggregates up to 100 μm in size, therefore it can be studied just by specific techniques. Using micro-Raman spectroscopy it was shown that vibrations of SbSe₃ groups, display much higher frequency due to the almost twice mass of selenium compared to sulphur. These results demonstrate the application of Raman spectroscopy for micro-identification of sulphide/selenide minerals and for precise studies of anion isomorphs in different mineral phases.

Figure: Raman spectra of the three mineral members along the CuSbS₂-CuSbSe₂ join, together with their micrographs and the depicted structure for příbramite.

References
[1] Jiří Sejkora, Elena Buixaderas, Pavel Škácha, Jakub Plášil, Micro-Raman spectroscopy of natural members along CuSbS₂-CuSbSe₂ join, J. Raman Spectroscopy 49, 1364 (2018) [doi: 10.1002/jrs.5395].