Vibrational spectroscopy of selected minerals of the rosasite group

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 similar to 3401 and 3311 cm(-1). Two intense bands observed at similar to 1096 and 1046 cm(-1) are assigned to nu(1)(CO3)(2-) symmetric stretching vibration and the delta OH deformation mode. Multiple bands are found in the 800-900 and 650-750 cm(-1) regions attributed to the nu(2) and nu(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 similar to 560 cm(-1) is assigned to a CuO stretching mode. (c) 2006 Elsevier B.V. All rights reserved.