Study on Gemmological and Mineralogical Characteristics of“Silver Line Stone”

A kind of cheap gem material——“Silver Line Stone”，which is recently sold in Guangzhou market，has been identified as enstatite by some testing institutions.In order to name this kind of stone and to provide useful information for the identification work，this paper investigates the“Silver Line Stone”samples by using the conventional gemmological methods and large－scale instruments（EPMA，IR，XRD and SEM）.The results show that the“Silver Line Stone”is characterized by this appearance：black，grey black and metallic luster reflecting light band.Its refractive index is 1.69，its Mohs’hardness is 5～6，and its density is 3.45g/cm³.It is mainly composed of hypersthene——a subspecies of orthorhombic pyroxene.The appearance of the“Silver Line Stone”may be caused by the micro－fine fiber structure of hypersthene and the angular arrangement of the contiguous fibrous bands.“Silver Line Stone”could be easily distinguished from enstatite by its appearance characteristics and higher density.