Forsterite Raman

The detailed structure of forsterite, Mg2Si04, an olivine-type material, has been studied by both vibration-rotation and e.p.r. spectroscopy. The i.r. and Raman spectra of various isotopically substituted species of forsterite have been measured new assignments of the bands have been obtained from a group-theoretical analysis of the olivine structure and the Mg— Mg and Si— Si isotopic shifts. The e.p.r. spectrum of low concentrations of Fe + cations in synthetic forsterite has been observed at 9 GHz and 35 GHz. It is concluded from the results that the Fe + cations are ordered in the octahedral M(2) sites of the olivine-type structure neither the valence state nor the site occupancy of the Fe cations is altered by heat treatment up to 110 C. 

Numerous spectral data appeared on natural forsterite as result of its continuous wavelength (CW) Raman spectra study under 532 and 780 nm laser excitations where Raman signals are accompanied by multiple luminescence lines and bands. Those luminescence spectral data exhibit much more emission centers than the... 

Such kind of Ct + luminescence is rather typical for natural forsterite. For example. Figure 5.44 presents luminescence features of several forsterite samples detected drrring Raman spectra study (http //rruff.info). Luminescence bands peaking at 740-750 nm rmder excitation by 532 nm at 300 K may be ascribed to Cr + in intermediate and strruig crystal fields. 

Jasinevicius R (2009) Characterization of vibrational and electronic features in the Raman spectra of gemstones. MSc thesis. Department of Geosciences, University of Arizona, Tucson, 147 p Jia W, Liu H, Jaffe S, Yen W (1991) Spectroscopy of Cr and Cr" ions in forsterite. Phys Rev B 43 5234-5242... 

Fig. 5 DFT calculated and experimental Raman spectra of crystalline Forsterite (5/a and 5/c) and Na2Si03 X 9 H2O color assignments on 5/b are the same as those on Fig. 3 for the dissolved silicates (e.g.. Figs 3/a and 3/d).

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