Traces of structural H2O molecules in baryte

Author(s)
Anton Beran, Dominik Talla, Zdenek Losos, Jiri Pinkas
Abstract

The infrared (IR) spectra of gem-quality barytecrystals from different occurrences are characterized byrelatively weak but strongly pleochroic absorption bands at3,280, 3,220, 3,155, and 3,115 cm-1. These bands areassigned to anti-symmetric and symmetric OH stretchingvibrations of two types of H2O molecules localized onvacant Ba sites. The H-H axis of the H2O I molecule isslightly tilted from the a-axis direction, its twofold axisbeing nearly parallel to the b-axis, thus defining the planeof the H2O molecule practically parallel to (001). The H2OII molecule has its H-H axis parallel to the b-axis direction,with its plane lying approximately parallel to (101). Thevalues of the total water contents of the baryte crystals,calculated on the basis of IR spectroscopic data, areranging from about 1.7-3.8 wt.ppm. The possible presenceof H3O? ions is also discussed.

Organisation(s)
Department of Mineralogy and Crystallography
External organisation(s)
Masaryk University
Journal
Physics and Chemistry of Minerals
Volume
37
Pages
159-166
No. of pages
8
ISSN
0342-1791
Publication date
2010
Peer reviewed
Yes
Austrian Fields of Science 2012
1030 Physics, Astronomy, 105116 Mineralogy
Portal url
https://ucrisportal.univie.ac.at/en/publications/2f82ae4e-c8dd-4f63-ad6f-bbc7bc753f12