黑色海水珍珠和人工处理黑珍珠的光谱学特征研究

Study on Spectral Characteristics of Black Saltwater Pearls and Treated Black Pearls

选用天然黑色海水珍珠、活性超级黑染色黑珍珠、辐照处理黑珍珠和硝酸盐染色黑珍珠,对其进行拉曼光谱测试、紫外可见吸收光谱测试的研究。两项测试表明:拉曼光谱中天然黑色海水珍珠、硝酸银染色和辐照黑珍珠均出现1080cm-1和699cm-1文石的特征拉曼峰,辐照黑珍珠荧光背景较强,染料染色黑珍珠的出峰位置与所使用染料的类型有关;紫外可见吸收光谱中,天然黑色海珍珠出现284nm和357nm两个吸收峰,染料活性超级黑染色珍珠出现380nm吸收峰,应为357nm吸收峰发生红移所致,银盐染色黑珍珠和辐照处理黑珍珠紫外区吸收峰消失。根据拉曼和紫外可见光谱特征,可以快速、无损地鉴定天然黑色珍珠和各种着色黑珍珠。

Raman spectrum and ultraviolet （UV） visible absorption spectrum of natural black saltwater pearls, dyed black pearls and radiated black pearls are analyzed and compared. It is found that natural black pearl, silver salt dyed pearl and radiated black pearl all have two peaks at 1080 and 699 cm 1 in raman spectrum. The fluorescence background of radiated black pearl is stronger. The peaks of dyed black pearl are correlated with the species of dyestuff. In UV-visible absorption spectrum, natural black pearl shows peaks at 284 and 357 nm, dyed black pearl has a peak at 380 nm, accounting for the displacement of 357 nm, while the peaks in ultraviolet region of silver salt dyed and radiated black pearl disappear. According to Raman and UV-visible spectral characteristics, non-destructive and effective identification of natural and color-treated black pearls is possible.