Original paper

Raspberry-red grossular from Sierra de Cruces Range, Coahuila, Mexico

Geiger, Charles A.; Stahl, Andreas; Rossman, George R.

European Journal of Mineralogy Volume 11 Number 6 (1999), p. 1109 - 1114

9 references

published: Nov 29, 1999
manuscript accepted: May 18, 1999
manuscript received: Dec 4, 1998

DOI: 10.1127/ejm/11/6/1109

BibTeX file

ArtNo. ESP147051106018, Price: 29.00 €

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Abstract

Abstract A raspberry-red grossular from the Sierra de Cruces Range in the state of Coahuila in Mexico has been investigated. Electron-microprobe analysis and 57Fe Mössbauer and UVYVIS spectroscopy were used in order to investigate the nature of the unusual red colour. The composition of the garnet is approximately (Ca2.94Mg009Mn2+0.10)313(Al1.90Fe3+0.05Mn3+0.01)1.96Si2.97O12. The UV/VIS spectrum is characterised by an absorption envelope centred around 19,000 cm1 in the green region, which can be fitted with two bands located at 19,503 and 17,302 cm-1, originating from two spin-allowed dd-electron transitions. They result from the presence of Mn3+ on the octahedral site of point symmetry 3¯.

Keywords

colour in mineralsgarnetUV/VIS spectroscopyMössbauer spectroscopy.