ASIAN JOURNAL OF CHEMISTRY, vol.24, no.5, pp.1941-1944, 2012 (SCI-Expanded)
The Raman spectroscopy is performed for the first time on the new discovered secondary copper arsenate mineral, lapeyreite [Cu3O[AsO3(OH)](2)center dot 0.75H(2)O]. The bands attributed to two main vibrating (CuO5 and AsO4) units are readily identified in the Raman spectrum. Symmetric stretching modes at 1047 cm(-1) and at 627 and 405 cm(-1) are assigned to (v(1))CuO5, (v(2))AsO4 and (v(3))AsO4 units, respectively. Bending vibration modes in the Raman spectrum are assigned to (v(2))AsO4 units at 214, 198 and 188 cm(-1) and to (v(2))CuO5 units at 141 and 100 cm(-1). In addition, As-O bond and O-H-O bond lengths in the structure of lapeyreite were assigned from the FT-IR at 3420, 2870 and 1640 cm(-1). The position and the intensity of both Raman vibrations reveal that the secondary occurring lapeyreite mineral is hydrothermally altered from the primary occurring cuprite mineral.