Vibrational spectroscopy of selected minerals of the rosasite group

Abstract: Minerals in the rosasite group namely rosasite, glaucosphaerite, kolwezite, mcguinnessite have been studied by a combination of infrared and Raman spectroscopy. The spectral patterns for the minerals rosasite, glaucosphaerite, kolwezite and mcguinnessite are similar to that of malachite implying the molecular structure is similar to malachite. A comparison is made with the spectrum of malachite. The rosasite mineral group is characterised by two OH stretching vibrations at ∼3401 and 3311cm−1. Two intense bands observed at ∼1096 and 1046cm−1 are assigned to ν 1(CO3)2− symmetric stretching vibration and the δ OH deformation mode. Multiple bands are found in the 800–900 and 650–750cm−1 regions attributed to the ν 2 and ν 4 bending modes confirming the symmetry reduction of the carbonate anion in the rosasite mineral group as C 2v or C s. A band at ∼560cm−1 is assigned to a CuO stretching mode. [Copyright &y& Elsevier]