广西陆川蛇纹石玉的岩相结构及成矿机理

Mineral Structure and Mineralization Mechanism of Serpentine Jade from Luchuan,Guangxi Province

应用外束质子激发X射线荧光光谱法、X射线衍射、激光拉曼光谱、扫描电子显微镜等无损分析技术,对广西陆川蛇纹石玉的成分、物相和结构进行分析。X射线衍射结果显示样品的衍射峰主要位于0.724、0.456、0.362、0.248、0.153和0.150 nm处,表明陆川蛇纹石玉主要矿物成分是蛇纹石,同时伴生方解石矿物与蛇纹石形成穿插交织结构。成矿机理分析表明,陆川蛇纹石玉是由白云质大理岩热液交代作用形成的,和广东的信宜玉均属于富镁碳酸盐型蛇纹石。拉曼光谱显示叶蛇纹石的特征峰位于229、376、457、686和1046 cm-1处,纤蛇纹石的特征峰位于228、345、386、624、690和1102 cm-1处,通过激光拉曼光谱可以快速区分陆川蛇纹石玉中纤蛇纹石和叶蛇纹石两种不同结构的蛇纹石亚种。

The nondestructive analysis techniques of Proton Induced X-ray Emission （PIXE） , X-ray Diffraction （XRD）, Laser Raman Spectroscopy （LRS） and Scanning Electron Microscopy （SEM） were applied to analyze the chemical composition and mineral structure of serpentine jade from Luchuan, Guangxi Province. The major XRD bands of the samples located at 0. 724, 0. 456, 0. 362, 0. 248, 0. 153 and 0. 150 nm, indicate that the major mineral of Luchuan jade is serpentine. Meanwhile, inte^q3enetration texture was formed between serpentine and associated calcite. Luchuan serpentine jade was formed by hydrothermal metasomatism from dolomitic marble, and both Luchuan Jade and Xinyi Jade belong to Mg-rich carbonate type serpentine. Raman characteristic bands of antigorite located at 229, 376,457, 686 and 1046 cm^（-1） while that of chrysotile occurred at 228, 345, 386, 624, 690 and 1102 cm^（-1）. Therefore, the Raman spectroscopy can be used to identify chrysotile and antigorite of the serpentine minerals of Luehuan jade.