Raman spectroscopic study of a hydroxy-arsenate mineral containing bismuth-atelestite Bi2O(OH)(AsO4)

The Raman spectrum of atelestite Bi2O(OH)(AsO4), a hydroxy-arsenate mineral containing bismuth, has been studied in terms of spectra-structure relations. The studied spectrum is compared with the Raman spectrum of atelestite downloaded from the RRUFF database. The sharp intense band at 834 cm(-1) is assigned to the vi AsO43- (At) symmetric stretching mode and the three bands at 767,782 and 802 cm(-1) to the v(3) AsO43- antisymmetric stretching modes. The bands at 310, 324, 353, 370, 395, 450, 480 and 623 cm(-1) are assigned to the corresponding v(4) and v(2) bending modes and Bi-O-Bi (vibration of bridging oxygen) and Bi-O (vibration of non-bridging oxygen) stretching vibrations. Lattice modes are observed at 172,199 and 218 cm(-1). A broad low intensity band at 3095 cm(-1) is attributed to the hydrogen bonded OH units in the atelestite structure. A weak band at 1082 cm(-1) is assigned to delta(Bi-OH) vibration. (C) 2010 Elsevier B.V. All rights reserved.