激发波长为473nm的光致发光光谱特征对珍珠类型及其颜色成因的指示意义

The Significance of Photoluminescence Spectra With the Excitation Wavelength of 473 nm for the Indication of Pearl Types and Color Origin

通过激发波长为473 nm的光致发光光谱对不同颜色珍珠的光致发光特征进行了对比研究,结果表明:(1)颜色未经处理的灰色、黄色、紫色和橙色珍珠的光致发光光谱峰值在570~600 nm区间,与文石的峰值一致,推测其颜色主要与文石排列结构有关。(2)颜色未经处理的紫色和橙色珍珠在500~570 nm区间内出现与文石无关的发光峰,推测其颜色还同样受有机质的影响。(3)颜色未经处理黑珍珠的峰值在800~900 nm之间,推测其黑色调主要与有机质有关。(4)经染色处理珍珠的峰值主要位于650~750 nm区间内,主要与染剂有关,而不同颜色染色珍珠具有类似的发光特征说明染色珍珠所用染剂致色成分可能有相似的基团组成。相关研究成果可为珍珠的检测鉴定、颜色成因研究提供更多科学依据。

In this paper,photoluminescence spectra with an excitation wavelength of 473 nm are used to study and compare the photoluminescence features of pearls of different colors.The results show that there are obvious differences in the photoluminescence spectra of pearls of different color types obtained under the wavelength of excitation light source,which has important indication significance for the origin of the color of pearls:(1)Most of the gray and yellow pearls with untreated color range from 570 to 600 nm,which is consistent with the main luminescent peaks of aragonite.It is inferred that the color origin is mainly related to the arrangement structure of aragonite.(2)The strongest luminescence peaks of untreated purple and orange pearls are also located in the range of 570~600 nm,related to aragonite.Still,a series of small sharp luminescence peaks,which have no relationship with aragonite,also appear in the range of 500~570 nm.It is inferred that the color is related to the arrangement structure of aragonite and influenced by organic matter in such pearls.(3)The main photoluminescence peak of untreated black pearls occurs from 800 to 900 nm,and the origin of its color may be mainly related to the organic matter in the pearls.(4)The strongest photoluminescence peak of most dyed pearls is located in the range of 650~750 nm,and the photoluminescence peak is mainly related to the dye.The similar photoluminescence characteristics of dyed pearls of different colors indicate that the main chromic components of the dyes currently used in the market have similar group compositions.The related research results can provide a more scientific basis for detecting and identifying pearls and studying color origin.