An infrared spectroscopic study of hydrogen feldspar (HAlSi₃O₈)

authored by

H. Behrens, G. Muller

Abstract

Hydrogen in H-feldspar obtained by ion-exchange was studied in the spectral range 1000-5500 cm^-1 by single crystal IR microspectroscopy. Spectra were almost identical for H-feldspars prepared either from sanidine or from adularia. Two bands in the middle-infrared were identified by D/H exchange as OH vibration modes. One broad band with a maximum at 3000 cm^-1 and shoulders at 2800, 3200 and 3500 cm^-1 confirms previous work. An additional OH absorption band with a maximum at 2485 cm^-1 was observed for the first time in feldspars. The pleochroisms of the OH absorption bands suggests that the H-feldspar is composed of two phases, an amorphous phase and a feldspathic phase. The experimental results imply that hydrogen is incorporated in the H-feldspars as protons attached to bridging oxygen as well as to non-bridging oxygen. The complex structure of the IR spectra implies that the protons are distributed over a large number of sites in the cation cavity of the feldspars. -from Authors

Organisation(s)

Institute of Mineralogy

Type

Article

Journal

Mineralogical magazine

Volume

59

Pages

15-24

No. of pages

10

ISSN

0026-461X

Publication date

03.1995

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Geochemistry and Petrology

Electronic version(s)

https://doi.org/10.1180/minmag.1995.59.394.02 (Access: Closed)