Abstract

Staurolite exhibits a complex IR absorption band system in the range of 3750 to 3250 cm (super -1) due to OH stretching vibrations. The bands show a strong pleochroism with nearly no absorbance in spectra with E//b and strong (intermediate) absorbance in spectra with E//a (E//c). The total integrated absorbance was determined from spectra of (010) staurolite plates. These spectra were polarized with E//a and E//c. The total integrated molar absorption coefficient (epsilon (sub i.tot) = 83000+ or -5000 l.mol H 2 O-1.cm (super -2) ) was calculated using H 2 O contents as determined from independent physico-chemical measurements ("Karl-Fischer" titration). Based on Lambert-Beer's law, the content of the component H 2 O in staurolite is obtained with a relative standard deviation of 9% (1sigma ) using this epsilon (sub i.tot) value and by measuring the total integrated absorbance of the whole band system from polarized spectra of a (010) staurolite plate. The quantitative IR data on staurolite are in good agreement with the IR absorption calibrations for water in minerals by Paterson (1982) and Libowitzky & Rossman (1997).

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.