Portal de Periódicos da CAPES

Comment on: Application of Raman Spectroscopy to Distinguish Metamorphic and Igneous Zircon (Xian et al., Anal. Lett. 2004, v. 37, p. 119)

2005; Taylor & Francis; Volume: 38; Issue: 4 Linguagem: Inglês

10.1081/al-200050353

1532-236X

Lutz Nasdala, John M. Hanchar,

Nuclear materials and radiation effects

Abstract We critically discuss a recently proposed technique ((Xian et al. 2004 Xian, W. S., Sun, M., Malpas, J., Zhao, G. C., Zhou, M. F., Ye, K., Liu, J. B. and Phillips, D. I. 2004. Application of Raman spectroscopy to distinguish metamorphic and igneous zircons. Anal. Lett., 37: 119–130. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar])) used to distinguish igneous (i.e., magmatic) from metamorphic growth of the mineral zircon according to the intensity of the 1461 cm−1 band observed in those author's Raman spectra. The band evaluated by Xian et al. (2004) Xian, W. S., Sun, M., Malpas, J., Zhao, G. C., Zhou, M. F., Ye, K., Liu, J. B. and Phillips, D. I. 2004. Application of Raman spectroscopy to distinguish metamorphic and igneous zircons. Anal. Lett., 37: 119–130. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] is actually due to laser‐induced photoluminescence of trace amounts of the trivalent rare earth element Er, which, as an analytical artefact, overlays the Raman spectrum when green Ar+ laser excitation is used. We demonstrate that this band is not a Raman band, and discuss why the intensity of Er3+ luminescence is not uniquely indicative of the geologic origin of a zircon crystal. The technique proposed by Xian et al. (2004) Xian, W. S., Sun, M., Malpas, J., Zhao, G. C., Zhou, M. F., Ye, K., Liu, J. B. and Phillips, D. I. 2004. Application of Raman spectroscopy to distinguish metamorphic and igneous zircons. Anal. Lett., 37: 119–130. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] may consequently lead to wrong, and thus misleading results. Therefore, we suggest that this technique should not be used for any petrogenetic assignment of the environment of crystallization for zircon.