Raman spectroscopy of beaverite and plumbojarosite

Raman spectroscopy has been used to characterise the compound of formula Pb(Fe3+, Cu2+)(3)(SO4)(2)(OH)(6), equivalent to synthetic beaverite, one of the jarosite subgroup minerals. The mineral is characterised by multiple OH stretching vibrations attributed to non-equivalent OH units in the structure. Multiple vibrations are observed for the SO42- stretching vibrations indicating the non-equivalence of the sulphate units in the structure. This multiplicity is also reflected in the nu(2) and nu(4) bending modes. The Raman spectrum of beaverite is significantly different from that of plumbojarosite, for which multiple bands are not observed. Copyright (c) 2005 John Wiley & Sons, Ltd.