Raman and infrared spectroscopic characterization of the phosphate mineral paravauxite Fe2+Al2(PO4)2(OH)2 8H2O

Frost, Ray L. and Scholz, Ricardo and Lopes, Andres and Xi, Yunfei and Žigovečki Gobac, Željka and Campos Horta, Laura Frota (2013) Raman and infrared spectroscopic characterization of the phosphate mineral paravauxite Fe2+Al2(PO4)2(OH)2 8H2O. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 116. pp. 491-496.

[img] PDF
Restricted to Registered users only
Language: English

Download (1MB)

Abstract

We have undertaken a vibrational spectroscopic study of paravauxite the Siglo XX mine, Bustillo Province, northern of Potosí department, Bolivia. This mine is important source for rare and unusual secondary phosphate minerals and is the type locality for a number of rare phosphates such as vauxite, sigloite, metavauxite and for jeanbandyite. The chemical formula of the studied sample was determined as Fe2þ 0:95; ðAl0:07ÞR1:02ðAlÞ2:09ðPO4Þ1:97ðOHÞ1:98 7:90ðH2OÞ. The Raman spectrum is dominated by an intense Raman band at 1020 cm 1 assigned to the PO3 4 m1 symmetric stretching mode. Low intensity Raman bands found at 1058, 1115 and 1148 cm�1 are assigned to the PO3� 4 m3 antisymmetric stretching vibrations. Raman bands of paravauxite at 537, 570, 609 and 643 cm�1 are assigned to the m4 PO3� 4 bending modes whilst the Raman bands at 393 and 420 cm�1 are due to the m2 PO3� 4 bending modes. The Raman spectral profile of paravauxite in the hydroxyl stretching region is broad with component bands resolved at 3086, 3215, 3315, 3421, 3505 and 3648 cm�1. Vibrational spectroscopy enables the assessment of the molecular structure of paravauxite to be undertaken.

Item Type: Article
Keywords: Paravauxite, Phosphate, Raman spectroscopy, Infrared spectroscopy
Date: 2013
Subjects: NATURAL SCIENCES > Geology > Mineralogy and Petrology
Divisions: Faculty of Science > Department of Geology
Depositing User: Danica Vujičić
Date Deposited: 13 May 2015 17:06
Last Modified: 13 May 2015 19:55
URI: http://digre.pmf.unizg.hr/id/eprint/3677

Actions (login required)

View Item View Item