Abstract: | Raman spectroscopy has been used to characterize the antimonate mineral bahianite Al5Sb35+O14(OH)2, a semi‐precious gemstone. The mineral is characterized by an intense Raman band at 818 cm−1 assigned to Sb3O1413− stretching vibrations. Other lower intensity bands at 843 and 856 cm−1 are also assigned to this vibration, and this concept suggests the non‐equivalence of SbO units in the structure. Low‐intensity Raman bands at 669 and 682 cm−1 are probably assignable to the OSbO antisymmetric stretching vibrations. Raman bands at 1756, 1808 and 1929 cm−1 may be assigned to δ SbOH deformation modes, while the bands at 3462 and 3495 cm−1 are assigned to AlOH stretching vibrations. The complexity in the low wave number region is attributed to the composition of the mineral. Copyright © 2009 John Wiley & Sons, Ltd. |