蒙古国某地绿松石玉的矿物组成及其成因

Mineral Composition and Genesis of Turquoise Jade at a Place of Mongolia

绿松石玉是主要由含水的铜铝磷酸盐矿物-绿松石组成的一种珍贵玉石,在珠宝市场上深受消费者青睐。本文通过偏光显微镜、电子探针、激光拉曼光谱测试技术对产自蒙古国某地的绿松石玉样品的矿物组成、成因及拉曼光谱进行分析研究,推断了该地绿松石玉样品的矿床成因类型,以期为今后优质绿松石玉的找矿勘查提供相关参考资料。结果显示:蒙古国绿松石玉由主要矿物绿松石和次要矿物石英、白云母、黄铁矿、黄铜矿、铜蓝及辉铜矿等组成,推测该绿松石玉样品产自硫化物矿床的次生富集带,其矿床类型属于原生多金属硫化物矿床经由风化淋滤形成的次生富集带型。该地绿松石与其他产地绿松石的拉曼光谱存在差异,推测可能由于绿松石中水的存在方式和含量、阴离子的种类和数量、元素的类质同象置换及产地的气候条件等影响所致。

Turquoise jade is a kind of precious jade mainly composed of turquoise,a hydrated copper aluminum phosphate,highly favored by consumers in the jewelry market.This work analyzed the mineral composition,genesis and Raman spectra characteristics of 12 samples of this jade from a place of Mongolia by using polarizing microscopy,EPMA and laser Raman spectroscopy.Then the genetic type of the turquoise jade deposit from which the samples came was inferred,in order to provide useful information for high quality turquoise prospecting and exploration in the future.The results show that the Mongolia turquoise comprises the primary mineral turquoise and secondary minerals including quartz,muscovite,pyrite,chalcopyrite,covellite and chalcocite,etc.Therefore,it can be speculated that this jade formed in a secondary enrichment zone of primary polymetallic sulfide deposits by weathering and leaching.There is a difference between the turquoise samples in Raman peaks of this place and the other origins.It is speculated that such a difference is related with the effects of some factors such as the existing way and content of water,the type and quantity of anions,and the trace element replacement in the turquoise and climatic conditions of the origin place.