“缅绿料”石英质玉的宝石矿物学及谱学表征  

Gemstone Mineralogical and Spectroscopic Characteristics of Quartzose Jade(“Mianlv Yu”)

作　　者：余炼钢 刘衔宇 陈全莉[3] YU Lian-gang;LIU Xian-yu;CHEN Quan-li(Dehong Teachers College,Dehong 678400,China;College of Jewelry,Shanghai Jian Qiao University,Shanghai 201306,China;Gemmological Institute,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]德宏师范高等专科学校,云南德宏678400 [2]上海建桥学院珠宝学院,上海201306 [3]中国地质大学(武汉)珠宝学院,湖北武汉430074

出　　处：《光谱学与光谱分析》2023年第8期2543-2549,共7页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(41874105);青年科学基金项目(41802042);云南省教育厅科学研究基金项目(2021J1166)资助。

摘　　要：“缅绿料”是近年来滇西市场上出现的新兴缅甸石英质玉石品种,特点是质地细腻,绿色带深浅不同的蓝、黄色调,部分绿色品种与高品质澳洲绿玉髓较为相似,但其颜色成因尚不清楚,鉴定评价及市场推广亦亟需相关理论支持。运用红外光谱仪、拉曼光谱仪、紫外-可见光谱仪、X射线荧光光谱仪、X射线粉末衍射仪、岩矿薄片鉴定等方法对“缅绿料”的矿物组成及结构、化学成分、谱学特征及颜色成因等进行探究。结果表明主要矿物为α-石英(含微量斜硅石),以隐晶质为主,少量微晶质,含量占90%以上,其次为显微细粒状、鳞片状绢云母及镍滑石,以及微量镍绿泥石、铬钙钛矿,局部偶见次生浸染状铁泥质,整体呈含鳞片显微粒状结构。红外透射光谱主要显示α-石英的红外吸收特征,1019、800~600和462 cm^(-1)处吸收峰分别归属于νas(Si—O—Si)反对称伸缩振动、νs(Si—O—Si)对称伸缩振动及δ(Si—O)弯曲振动。3463及1639、1399 cm^(-1)处吸收峰由赋存于石英微空隙间的自由水分子的νas(H—O—H)反对称伸缩振动及δ(H—O—H)弯曲振动引起。拉曼光谱除显示α-石英特征拉曼组峰204、262、355、395、463 cm^(-1)外,501 cm^(-1)处的弱拉曼峰指示含微量斜硅石,675 cm^(-1)处拉曼峰指示含镍滑石。综合化学成分及紫外-可见光谱特征表明,该玉石含Mg、Al、Cl、K、Ca、Ti、Cr、Fe、Ni等杂质元素,Ni和Fe是主要致色元素。Ni、Fe含量的显著差异是其呈现绿-蓝绿、绿黄-黄绿两种颜色系列的原因。高含量Ni、低含量Fe形成绿-蓝绿色系列,蓝色调变化与Ni含量呈正相关性;同等低含量的Ni和Fe形成绿黄-黄绿色系列,黄色调变化与Fe、Ni含量呈负相关性。综上,“缅绿料”归属为绿玉髓,其颜色特征由镍滑石、绢云母及次生铁泥质等杂质矿物引起,Ni元素以游离态Ni离子和杂质矿物镍滑石两种形式存在,其中镍滑石在�In recent years,a new kind of quartzose jade named“Mianlv Yu”from Myanmar has emerged in the west Yunnan jewelry market.It is characterized by delicate texture,and green color with different blue and yellow tones,and some green are similar to high-quality Australian green chalcedony.However,the color origin of this jade is still unclear,and there is still a lack of relevant theoretical support for its species identification,quality evaluation,and market promotion.In this paper,the mineral composition and structure,chemical constituent,spectral characteristics,and color origin of this jade were studied using an Infrared spectrometer,Raman spectrometer,UV-vis spectrometer,X-ray fluorescence spectrometer,X-ray powder diffractometer,and Polarizing microscope.The results show that the main mineral isα-quartz(containing trace Moganite),mainly cryptocrystalline,and a small amount of microcrystalline,accounting for more than 90%of the content,followed by sericite and willemsite in the form of microgranular and scaly,and extremely trace amounts of nepouite and chromceladonite.Occasionally,there is secondary disseminated iron clay in the local position,and the whole structure is microgranular with scales.The infrared transmission spectrum mainly shows the infrared absorption characteristics ofα-quartz,Infrared absorption peaks at 1019,800~600,and 462 cm^(-1)are attributed to the anti-symmetric stretching vibration ofνas(Si—O),and the symmetric stretching vibration ofνs(Si—O—Si)and the bending vibration ofδ(Si—O),respectively.The characteristic absorption peaks at 3463,1639,and 1399 cm^(-1)are caused by the anti-symmetric stretching vibrationνas(H—O—H)and bending vibrationδ(H—O—H)of free water molecules between quartz microvoids.In the Raman spectrum test,except for the Raman group peaks 204,262,355,395,and 463 cm^(-1)indicated the characteristics ofα-quartz,the weak Raman peak at 501 cm^(-1)indicated the presence of trace Moganite,and the Raman peak at 675 cm^(-1)indicated the presence of willem

关 键 词：“缅绿料” 石英质玉 矿物组成 谱学特征 颜色成因 

分 类 号：P575[天文地球—矿物学]