Location characteristics of tremolite jade from Dahua, Guangxi

Abstract

The tremolite jade found in Dahua County, Guangxi Province, is a new type of tremolite jade that has only appeared in the past two years with a low degree of research. But the jade in this production area occupies a large share in the market. It is of great significance to systematically study the gemological characteristics and origin attributes of tremolite jade in this area. Through routine tests, Raman spectroscopy (Raman), X-ray powder diffraction (XRD), inductively coupled plasma mass spectrometry (ICPMS), laser-induced breakdown spectroscopy (LIBS) and other tests, the inclusion characteristics, spectral characteristics, structural characteristics and composition characteristics of tremolite jade in this area are studied to interpret the origin attribute of tremolite jade in this area. The results show that the main mineral components of Dahua tremolite jade are relatively stable, such as SiO2, MgO and CaO, While the coefficient of variation of minor mineral components MnO, FeO and TiO2 is relatively large. The contents of trace elements B, Cr, Zn and Sr are relatively high, the contents of V, Co and Ni are relatively low, and the content of Mg2+/(Mg2++Fe2+) is 0.03, indicating that the main mineral is tremolite and the tremolite jade in this area is formed by contact metasomatic metamorphism, characterized by low iron and high calcium; From the rare earth elements contained in the sample, the total amount of rare earth elements ΣREE of tremolite jade in the mining area is low, the differentiation of light and heavy rare earth elements is not obvious, belonging to the enrichment type of light rare earth elements, the rare earth distribution mode belongs to the right dip type, relatively flat, Eu negative anomaly and obvious Ce negative anomaly; The average crystallinity of tremolite jade in this area is 0.963, which is greater than that of Xinjiang tremolite jade by 0.843, which is close to that of Qinghai(0.96), which reflects that Dahua tremolite jade has high crystallinity, relatively large crystal particles and good crystallization environment; The ratio of beryllium/silicon intensity(IBe/ISi) by LIBS of tremolite jade in this area is: 0 for tremolite jade in Dahua, Guangxi, China, 0.003-0.008 for tremolite jade in Xinjiang, China, 0 for tremolite jade in Qinghai, China, 0.004-0.006 for tremolite jade in Liaoning, China, 0.1-0.16 for tremolite jade in Korea and 0.03-0.05 for tremolite jade in Russia. The comparison between the above information and other places of origin provides a reference for traceability