北海海水珍珠的谱学和化学组成特征

选取18颗北海海水养殖珍珠为研究对象,通过激光拉曼光谱仪、红外和紫外—可见—近红外光谱仪以及激光剥蚀电感耦合等离子体质谱仪分析,系统研究了北海珍珠的谱学和化学成分特征。谱学结果显示北海珍珠的红外—拉曼谱峰均与文石的官能团振动吻合,指示矿物成分为文石;紫外—可见—近红外谱峰是文石结构和有机致色分子共同作用的结果,其中,350~400nm范围内的两个弱峰可能是北海珍珠独有的特征峰;激光剥蚀电感耦合等离子体质谱分析结果显示北海珍珠具有高Mg、B、Sr、Na和K,低Mn、P和Ba的特征。北海珍珠的化学组成与典型海水珍珠相似,而与淡水珍珠有明显差别,因而可用于指示其生长环境。

Spectroscopical and Compositional Characteristics of Beihai Saltwater Pearls

18 grains of Beihai saltwater pearls were determined by Raman spectroscopy,infrared spectroscopy,ultraviolet-visible-near infrared spectroscopy(UV-VIS-NIR)and laser ablation inductively coupled plasma mass spectrometry to investigate their spectroscopic and compositional characteristics.The results of the infrared and Raman spectrum suggest that aragonite is the dominant mineral of the Beihai pearls.The UV-VIS-NIR absorption bands of the Beihai pearls are attributable to combined effect of aragonite structure and organic chromogenic molecules.The two weak absorption bands at 350~400 nm are unique and can be used as potential identification markers of Beihai pearls.Besides,the Beihai pearls has the characteristics of high Mg,B,Sr,Na and K,and low Mn,P and Ba.The compositional features of the Beihai pearls are rather similar to those of the saltwater pearls but significantly different from those of freshwater pearls,thus,they can be applied to indicate their grown environment.