陕西宁强“珊瑚玉”的矿物学、玉石学特征研究

Gemological characteristics of the Ningqiang coral jade from Shannxi Province

对市场上一种名为宁强"珊瑚玉"的玉石新品种进行了矿物学、玉石学特征研究。结果表明,宁强"珊瑚玉"是珊瑚骨骼孔隙被碳酸盐矿物充填所形成的化石,主要组成矿物为方解石,所含的其他矿物较少。宁强"珊瑚玉"密度2.71~2.72 g/cm^3,点测折射率1.50,玻璃至油脂光泽,半透明到不透明,质地细腻,光泽温润,颜色丰富,纹理变化多样,是优质的玉石材料。但由于"珊瑚玉"硬度较低,较难进行复杂的加工,比较适合用于加工素面首饰工艺品,着力表现其自身的生物结构和纹理特征。

Mineralogical and gemological characteristics of samples of the Ningqiang coral jade from Ningqiang County of Shannxi Province were identified,analyzed and studied.The results show that the Ningqiang coral jade is a kind of coral fossils formed by the infilling of coral bones and carbonate minerals in its pores,and mainly comprises calcite,with a few other minerals.Its densities vary in the range of 2.71 ~2.72 g/cm^3,with refractive index being 1.50.In spite of its low Moh's hardness,the Ningqiang coral jade is an excellent type of jade due to its fine matrix,various colors and laminations.It is thus held that,with its unique structures and laminations,this kind of jade is suitable for producing plain ornaments and handicrafts.