Zhi Y.-X.,Tongji University |
Zhi Y.-X.,Shanghai Engineering and Technology Research Center for Gem and Materials Technics |
Liao Z.-T.,Shanghai Engineering and Technology Research Center for Gem and Materials Technics |
Liao Z.-T.,Tongji University |
And 6 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2013
Nephrite samples coming from various origins were investigated using Fourier transform near-infrared spectroscopy (FTNIR). The result shows that samples from some specific origins display four absorption bands of OH stretching vibrations in the 7000~7400 cm-1 region, which are ascribed to overtone vibrations respectively of OH(MgMgMg), OH(MgMgFe2+), OH(MgFe2+Fe2+) and OH(Fe2+Fe2+Fe2+), are related to Mg2+ and Fe2+ ion located in M1 and M3 positions of tremolite crystalline structure. With the raise of Fe2+/(Fe2++Mg2+) ratio in tremolite, splitting and redshift of OH vibration bands proceed, gaining an increase in wavenumber, band number and band intensity. Significance of the OH NIR spectra in nephrite origin identification is discussed.