角质型珊瑚的鉴定特征研究

Identification of Horny Coral

角质型珊瑚分为黑珊瑚和金珊瑚,文章对市场上常见的角质型珊瑚品种进行样品收集,并通过常规宝石学、红外光谱、扫描电镜等测试分析,总结其鉴定特征。结果表明:黑珊瑚结构致密,无明显的小刺特征,金珊瑚表面为金属光泽,有纵纹,无小刺结构;红外光谱测试发现黑珊瑚绝大部分为有机质,不含或极少含碳酸盐成分,而金珊瑚中不仅含有有机质,也含有碳酸盐等矿物成分,如1413cm-1、875cm-1的峰值分别是方解石和文石的特征谱峰;扫描电镜下可以从微生长结构方面对角质型珊瑚进行鉴别,黑珊瑚生长层之间非常紧密,仅在表面有小刺;金珊瑚表面有纵纹,放大可见类似鳞片状的结构。

Horny corals were classified into Black Coral and Golden Coral. The paper collected samples of the horny corals in the market and summarized the identification characteristics with conventional gemological experiments and analysis tests of infrared spectrometer and SEM. The testing results indicated that the Black Coral structure was dense and no obvious small thorn structure; Golden Coral had the metallic luster, longitudinal lines inside, and no small thorn structure either. With Infrared spectroscopy, Black Coral was identified as organic matter in most parts with no or very few carbonate components. But Golden Coral contained organic matter and minerals such as carbonate, like as calcite and aragonite with characteristic spectrum peaks of 1413 cm^-1 and 875 cm^-1 . With scanning electron microscopy, the different growth micro-structures was observed, which was helpful to identify the horny corals： growth layers of Black Coral were very close with only small thorns on the surface, and Golden Coral had longitudinal lines on the surface, and visible similar flake structure with magnification.