中国三个产地蛇纹石玉的地质背景及宝石学特征

辽宁省岫岩县、山东省泰安县和青海省祁连县是中国市场上蛇纹石玉最主要的三个产地,不同产地的矿床特征及所产蛇纹石玉在外观、化学成分和红外光谱等方面存在较大差异。本文综合前人的研究成果,从地层、构造、矿体、形成时期、成因等角度对三个产地蛇纹石玉矿床的地质特征进行了归纳总结;通过收集三个产地蛇纹石玉的常规宝石学特征、电子探针分析数据及红外光谱测试数据,对这三个产地蛇纹石玉的基本宝石学性质、化学成分和红外光谱图进行了对比分析,总结了三个产地蛇纹石玉的鉴别特征。三个产地的蛇纹石玉在颜色、光泽、透明度、内含物等方面表现出不同的特征,在化学成分、微量元素、红外光谱特征方面也有明显的差异,这些鉴别特征在一定程度上都可以辅助判断产地。此外,蛇纹石玉的颜色与Fe元素有关,Fe含量越大,绿色越深。

Mineral Deposits and Gemological Characteristics of Serpentine Jades from Three Origins in China

Xiuyan County in Liaoning Province,Tai’an County in Shandong Province and Qilian County in Qinghai Province are the three main producing areas of serpentine jades in the Chinese market.Serpentine jades from different areas are quite different in deposit characteristics,appearance,chemical composition and infrared spectra.Based on previous research results,this article summarizes the geological characteristics of the serpentine jade deposits in the three producing areas from stratigraphy,tectonics,ore bodies,period of formation and genesis.By collecting the data of conventional gemological characteristics,electron microprobe analysis and infrared spectrum of serpentine jades from the three areas,this article compares and analyzes the basic gemological properties,chemical composition and infrared spectra of the serpentine jades from the three areas,and summarizes their identification characteristics.Serpentine jades from the three areas show different characteristics in colour,lustre,transparency,inclusions,chemical composition,trace elements and infrared spectrum characteristics.To a certain extent,these identifying characteristics can assist in judging the origin.In addition,the color of serpentine jade is related to element Fe,and the higher the Fe content,the darker the green.