Gemmological Characteristics of the “Jin Gao Yu” from Shangluo City, Qinling Mountains, Shaanxi Province, China

Abstract

In recent years, “Jin Gao Yu” that has been traded as a kind of jade has appeared in areas of the Luonan and Shangnan counties, Shangluo City, Shaanxi Province, attracting the attention of scholars and consumers for its delicate texture and warm color. In this study, infrared spectroscopy, Raman spectroscopy, X-ray diffraction analysis, and electron microprobe analysis were used to conduct a systematic gemmological test and an analysis of “Jin Gao Yu”. The results show that “Jin Gao Yu” is a compact mineral aggregate dominated by dolomite, which contains quartz mineral inclusions. The color of “Jin Gao Yu” is grayish-white to earthy-yellow, the refractive index is about 1.54, and the relative density is about 2.86. Its crystal structure is basically the same as that of dolomite, both of which are trigonal systems with granular crystalloblastic textures. It has good crystallinity. The recrystallization phenomenon can be seen under a polarizing microscope. This study determined the species of “Jin Gao Yu”, improved its gemological basic data, provided a theoretical basis for the identification of “Jin Gao Yu” in the future, and, also, provided a new direction for the use of dolomite.

Keywords

• Jin Gao Yu
• dolomite
• Shangluo
• Qinling
• Shaanxi province
• China