[Reserach on Raman spectra of organic ingredients on colored pearls].
Based on the visible spectra and Raman spectra test of a variety of colored pearls samples to study the relationship between the organic component and the pearl's color was studied. The study results show that both the freshwater and seawater pearls exhibit strong characteristic peaks in 1121-1132 and 1506-1524 cm(-1) range, which is respectively attributed to the C-C and C=C stretching vibration; the peak intensity in 1117-1132, 1502-1524 and 2000-3500 cm(-1) range increases as the color deepens, which is closely related to the pearl's color; The peak in the 1475-1575 cm(-1) range is divided into 8-10 secondary peaks of purple freshwater pearl and deep orange seawater pearl. The number of C=C double bonds is N=9 approximately 27 and N=7 approximately 27 respectively after calculation. Polyene compound of different varieties and content could be the reason for the pearls' color.
Yang
Y
Hu
Lu-Wei
LW
Fan
Yi-Lan
YL
Huang