Spectroscopic and bond-topological investigation of interstitial volatiles in beryl from Slovakia

Author(s)
Jana Fridrichová, Peter Bačík, Valéria Bizovská, Eugen Libowitzky, Radek Skoda, Pavel Uher, Daniel Ozdín, Martin Števko
Abstract

Nine beryl samples from Western Carpathians, Slovakia, were investigated by infrared and Raman spectroscopy and differential thermal analysis. Two types of water H

2O I and H

2O II were detected. Infrared spectroscopy proved the presence of water type I and II in the presence of alkali cations with several bands: (1) symmetric stretching vibration—ν

1; (2) antisymmetric stretching mode—ν

3; (3) bending vibration—ν

2. The presence of singly and doubly coordinated type II water (IIs and IId) was confirmed by single-crystal IR spectroscopy. From Raman spectra a band at 3606 cm

−1 was assigned to ν

1 of water type I and the range of 3597–3600 cm

−1 to water type II. The presence of doubly coordinating water indicates a relatively highly hydrated environment with the presence of alkali ions including Na as the dominant cation coordinated by H

2O II. CO

2 bands were detected only by single-crystal IR spectroscopy. Thermal analysis proved total water loss in the range of 1.4–2.0 wt% and three main dehydration events. Based on the study of bond-topological arrangements two molecules of H

2O IId are each bound with two H···O1 bonds and one Na–O

W bond with an angular distortion, and by releasing one H

2O molecule more stable H

2O IIs is produced. The H

2O I molecule is bound only by two equivalent hydrogen bonds. The H

2O IIs molecule with a Na–O

W bond strength of 0.28 vu and two H···O1 bonds of 0.14 vu without any forced angular distortion is the most stable of all.

Organisation(s)
Department of Mineralogy and Crystallography
External organisation(s)
Comenius University Bratislava, Slovak Academy of Sciences (SAS), Masaryk University
Journal
Physics and Chemistry of Minerals
Volume
43
Pages
419-437
No. of pages
19
ISSN
0342-1791
DOI
https://doi.org/10.1007/s00269-016-0806-9
Publication date
03-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
104026 Spectroscopy, 105116 Mineralogy
Keywords
ASJC Scopus subject areas
Geochemistry and Petrology, General Materials Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/04fec5a4-0044-4c09-874a-400bd3d64bf9