ON SOME CONTROVERSIALLY-DISCUSSED RAMAN AND IR BANDS OF BERYL

LÊ THỊ THU HƯƠNG, NGUYỄN TRUNG CHÍ

Faculty of Geology, Hà Nội University of Sciences, 334 Nguyễn Trãi, Hà Nội

Abstract: Natural emerald and synthetic analogues of the beryl gem variety from various deposits and manufacturers were investigated with Raman, IR spectroscopy, Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Electron Microprobe Analysis (EMPA). The Raman-band at 1067-1072 cm^-1 and the IR-band at 1071-1207 cm^-1 have been assigned till now either to Si-O or to Be-O by different studies. Basing on the finding that the position and Full Width at Half Maximum (FWHM) of these bands is related to the concentration of silicon, but not that of beryllium, it is concluded that these bands are generated by the vibration of Si-O.