广西大化县透闪石玉的产地特征

广西河池市大化瑶族自治县发现了透闪石玉矿床，研究程度较低，但是该产区玉石在市场上却占有不小份额，对该区透闪石玉的宝石学特征及其产地属性进行系统研究具有重要意义。通过常规测试、拉曼光谱（RAMAN）、X射线粉晶衍射（XRD）、电感耦合等离子质谱（ICP-MS）、激光诱导击穿光谱（LIBS）等测试，研究该区透闪石玉的包体特征、谱学特征、结构特征和成分特征，来解读本地区透闪石玉的产地属性。研究结果显示:大化透闪石玉的主要矿物成分SiO₂、MgO和CaO较为稳定，次要矿物成分MnO，FeO，TiO₂的变异系数相对较大，样品的微量元素B，Cr，Zn，Sr含量较高，V，Co，Ni的含量相对较低，Fe2+/（Mg2++Fe2+）平均值为0.03，显示主要矿物为透闪石，说明本区透闪石玉为镁质大理岩受到接触交代变质作用而形成，低铁，高钙为特征；从样品所含有的稀土元素来看，该矿区的透闪石玉稀土元素总量∑REE偏低，轻重稀土元素分异不明显，属于轻稀土元素富集型，稀土配分模式属于右倾型，比较平坦，Eu负异常，有明显的Ce负异常；透闪石玉结晶度平均值为0.963，大于新疆透闪石玉的结晶度平均值0.843，与青海的0.96相近，这反映出大化透闪石玉的结晶程度较高，晶体颗粒相对较大，结晶环境良好；透闪石玉中铍/硅LIBS强度比（I_Be/I_Si）为:中国广西大化透闪石玉为0，中国新疆透闪石玉0.003~0.008，中国青海透闪石玉为0，中国辽宁透闪石玉为0.004~0.006，韩国透闪石玉为0.1~0.16，俄罗斯透闪石玉为0.03~0.05。研究结果与其他产地的比对可为溯源提供参考。 

Location characteristics of tremolite jade from Dahua,Guangxi

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(I_Be/I_Si) 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.