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- Perchiazzi, Natale, et al.
(författare)
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Gabrielsonite revisited: crystal-structure determination and redefinition of chemical formula
- 2018
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Ingår i: European journal of mineralogy. - : Schweizerbart. - 0935-1221 .- 1617-4011. ; 30:6, s. 1173-1180
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Tidskriftsartikel (refereegranskat)abstract
- A reinvestigation of gabrielsonite from the holotype specimen from Långban, central Sweden, using single-crystal synchrotron X-ray diffraction, electron-microprobe techniques and Fourier-transform infrared (FTIR) spectroscopy, Raman and Mössbauer spectroscopies show that the mineral is an anhydrous Fe3+-bearing arsenite and not a hydrous Fe2+-bearing arsenate, as originally proposed. The revised ideal chemical formula of gabrielsonite is PbFe3(As3+O3)O. The mineral is related to the descloizite supergroup, but it differs through the valencies of the non-Pb cations Fe (M3+ vs. M2+) and As (3+ vs. 4+) and through lower coordination of Pb (4 vs. 7–8) and As (3 vs. 4). The redefinition of gabrielsonite (proposal 17-G) has been approved by the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association.
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