Original paper

Trace hydrogen in Verneuil-grown corundum and its colour varieties — an IR spectroscopic study

Beran, Anton

European Journal of Mineralogy Volume 3 Number 6 (1991), p. 971 - 976

21 references

published: Dec 19, 1991
manuscript accepted: May 13, 1991
manuscript received: Feb 18, 1991

DOI: 10.1127/ejm/3/6/0971

BibTeX file

ArtNo. ESP147050306005, Price: 29.00 €

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Abstract

Abstract IR spectra of Verneuil-grown colourless corundum, rose to deep red ruby, blue, “amethyst”- and “alexandrite”- coloured sapphire show a distinct variability in the region of the OH stretching fundamental. Hydrogen, bonded to oxygen, varies from approximately 1 to 3.5 ppm. Extremely pleochroic and narrow OH bands are centered at 3310, 3230 and 3185 cm-1. The OH dipoles are oriented perpendicular to the c-axis. Assuming vacancies in the cation lattice, OH is coordinated to two Al atoms forming "groups" of face-sharing Al2(OH)O8-double octahedra.

Keywords

corundumrubysapphirehydroxyl groupstrace hydrogeninfrared spectroscopygemmology