Micro-Raman Characterization of the Lapeyreite Mineral, the Alpes-Maritimes Region, Nice, France

摘要

The Raman spectroscopy is performed for the first time on the new discovered secondary copper arsenate mineral, lapeyreite [Cu3O[AsO3(OH)]2.0.75H2O]. 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,)CuOs, (v2)AsO4 and (v3)AsO4 units, respectively. Bending vibration modes in the Raman spectrum are assigned to (v2)AsO4 units at 214, 198 and 188 cm~(-1) and to (v2)CuO5 units at 141 and 100 cm~(-1). In addition, As-0 bond and O-H-O bond lengths in the structure of lapeyreite were assigned from the FT-IR at 3420, 2870 and 1640cm~(-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.