雪宝顶白钨矿的谱学特征及主微量元素分析  

Spectral Characteristics and Analysis of Main and Trace Elements of Scheelite From Xuebaoding

作　　者：曹沁元 史淼 马世玉 CAO Qin-yuan;SHI Miao;MA Shi-yu(School of Earth Sciences,Hebei GEO University,Shijiazhuang 050031,China;School of Gemmology and Materials Science,Hebei GEO University,Shijiazhuang 050031,China;Hebei Key Laboratory of Green Development of Rock Mineral Materials,Shijiazhuang 050031,China;Engineering Research Center for Silicate Solid Waste Resource Utilization of Hebei Province,Shijiazhuang 050031,China)

机构地区：[1]河北地质大学地球科学学院,河北石家庄050031 [2]河北地质大学宝石与材料学院,河北石家庄050031 [3]河北省岩石矿物材料绿色开发重点实验室,河北石家庄050031 [4]硅酸盐固废资源化利用河北省工程研究中心,河北石家庄050031

出　　处：《光谱学与光谱分析》2024年第6期1689-1696,共8页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(42002156);河北省自然科学基金项目(D2021403015);河北省高等学校科学技术研究项目(QN2021027);河北地质大学国家预研项目(KY2024YB01);河北省研究生创新项目(CXZZSS2023134和CXZZSS2024107)资助。

摘　　要：白钨矿是一种稀有宝石,具粒状、块状构造,颜色为白-浅黄色,油脂光泽,荧光性明显。四川平武雪宝顶白钨矿矿床为围岩蚀变较弱的脉状热液巨晶宝石级矿床,产出白钨矿颜色饱和度较高,具完美晶型且色泽纯正,与绿柱石、锡石和白云母共生。该研究选取雪宝顶近无色-橘黄色调白钨矿为研究对象,使用X射线粉晶衍射(XRD)、傅里叶变换红外光谱分析仪、紫外-可见分光光度计、激光拉曼光谱仪、电子探针、激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)的综合分析,结合矿物学、谱学与主微量元素特征,确定近无色-橘黄色调白钨矿的矿物成分、晶体结构、特征鉴别谱带、致色离子以及主微量、稀土等化学组分含量,探讨白钨矿稀土元素含量与颜色成因关系,为雪宝顶近无色-橘黄色调白钨矿提供诊断性鉴别依据。研究结果表明,白钨矿结晶程度较好,化学成分均匀,无明显间断,矿物成分含量相对集中,共生矿物多为白云母和伊利石。样品具典型的白钨矿红外特征峰440、809和870 cm^(-1)及与Ca_(2+)有关的448 cm^(-1)特征峰,谱峰显示色调越深者吸收度越高;拉曼特征峰909 cm^(-1)和Ca—O晶格振动峰207 cm^(-1),随色调加深强度加深;紫外吸收峰表现为橙黄区强吸收,尖峰在383、570、584和804 nm附近,近无色调者仅具383 nm尖峰,黄色调较浅者近紫外区Fe^(3+)吸收度较低,黄色调较深者蓝紫区Fe^(3+)强吸收且其橘黄色调由Nd^(3+)所致;白钨矿化学组分WO_(3)和CaO质量比接近甚至超过理想值,近无色者含量相对集中;微量元素中Fe元素与色调呈正相关,黄色调越深者,含量越高;稀土总量变化范围大,轻稀土更为富集,具明显的Eu负异常,Ce异常不明显。浅黄色调受微量元素Si、Fe元素及Fe^(3+)的d—d电子跃迁影响,黄色调受微量元素Mn、Fe元素及Fe^(3+)的电子跃迁所致,橘黄色调受稀土Nd和Sm元素影响较大。Scheelite is a rare gemstone with a massive granular structure,exhibiting a white to light yellow coloration,greasy luster,and obvious fluorescence.The scheelite deposit at Xuebaoding in the Pingwu region of Sichuan Province is a vein-like hydrothermal-type deposit with weak alteration of host rocks.Scheelite produced has a high color saturation,perfect crystal form,and pure color,associated with beryl,cassite and muscovite.The nearly colorless to orange tone scheelite from Xuebaoding was taken as the research object in this study.Comprehensive analysis was conducted using X-ray powder diffraction(XRD),Fourier infrared spectrum analysis,ultraviolet-visible spectrophotometer,laser Raman spectrometer,electron probe,and laser ablation inductively coupled plasma mass spectrometer(LA-ICP-MS).The mineral composition,crystal structure,characteristic identification spectral bands,color-causing ions,as well as the contents of the main and trace elements,rare earth and other chemical components of the nearly colorless to orange tone scheelite were determined by combining mineralogy,spectroscopy and main and trace elements characteristics.The relationship between rare earth element content and color genesis was also discussed.All have to provide the diagnostic basis for identification of nearly colorless to orange tone scheelite from Xuebaoding.The research results demonstrate that scheelite exhibits good crystallinity,displaying a uniform chemical composition without obvious discontinuity.The mineral composition is relatively concentrated,and the accessory minerals are mostly muscovite and illite.Significantly,scheelite's typical infrared characteristic peaks were observed at 440,809 and 870 cm^(-1),along with a peak at 448 cm^(-1)related to Ca_(2+).The spectral peak exhibits higher absorption for deeper color tones.In the same way,the Raman characteristic peak is at 909 cm^(-1),and the Ca—O lattice vibration peak is at 207 cm^(-1),with increasing intensity as the color tone deepens.Additionally,the ultraviolet absorptio

关 键 词：雪宝顶 白钨矿 近无色-橘黄色调 谱学特征 原位微区主微量元素特征 

分 类 号：P575.4[天文地球—矿物学]