Raman spectroscopic study of the tellurite mineral: sonoraite Fe3+Te4+O3(OH)•H2O

Tellurites may be subdivided according to formula and structure. Raman spectroscopy has been used to study sonoraite, an example of a tellurite with hydroxyl and water units in the mineral structure. The free tellurite ion will have C-3v symmetry and four modes, 2A(1) and 2E. An intense Raman band at 779 cm(-1) is assigned to the v, (TeO3)(2-) symmetric stretching mode. A band at 666 cm(-1) with a shoulder at 638 cm(-1) is assigned to the v(3) (TeO3)(2-) antisymmetric stretching mode. Bands at 374 and 387 cm(-1) and the two bands at 425 and 468 cm(-1) are assigned to the (TeO3)(2-) v(2) (A(1)) and (TeO3)(2-) v(4) (E) bending modes, respectively. The sharp band at 3423 cm(-1) assigned to the OH stretching vibration of the OH unit is superimposed upon a broader spectral profile with Raman bands at 3000, 3223, 3350 and 3450 cm(-1) which are attributed to water stretching bands. The technique of Raman spectroscopy is excellent for the study of tellurite minerals. Copyright (C) 2008 John Wiley & Sons, Ltd.