title: A SEM, EDS and vibrational spectroscopic study of the tellurite mineral: Sonoraite Fe(3+)Te(4+)O3(OH)·H2O.
abstract: We have undertaken a study of the tellurite mineral sonorite using electron microscopy with EDX combined with vibrational spectroscopy. Chemical analysis shows a homogeneous composition, with predominance of Te, Fe, Ce and In with minor amounts of S. Raman spectroscopy has been used to study the mineral sonoraite an examples of group A(XO₃), with hydroxyl and water units in the mineral structure. The free tellurite ion has C₃v symmetry and four modes, 2A₁ and 2E. An intense Raman band at 734 cm(-1) is assigned to the ν₁ (TeO₃)(2-) symmetric stretching mode. A band at 636 cm(-1) is assigned to the ν₃ (TeO₃)(2-) antisymmetric stretching mode. Bands at 350 and 373 cm(-1) and the two bands at 425 and 438 cm(-1) are assigned to the (TeOv)(2-)ν₂ (A₁) bending mode and (TeO₃)(2-)ν₄ (E) bending modes. The sharp band at 3283 cm(-1) assigned to the OH stretching vibration of the OH units is superimposed upon a broader spectral profile with Raman bands at 3215, 3302, 3349 and 3415 cm(-1) are attributed to water stretching bands. The techniques of Raman and infrared spectroscopy are excellent for the study of tellurite minerals.
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia. Electronic address: r.frost@qut.edu.au.
authors.forename: Ray L
authors.initials: RL
authors.lastname: Frost
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
authors.forename: Andrés
authors.initials: A
authors.lastname: López
authors.affiliation: Geology Department, School of Mines, Federal University of Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG 35400-00, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Scholz
keywords: Cliffordite; Infrared spectroscopy; Keystoneite; Raman spectroscopy; Sonoraite; Tellurite