DiamondView^TM在有机充填碧玺鉴定中的应用

目前主要通过放大检查和红外光谱分析等测试方法对有机充填碧玺进行鉴定,但它们在准确性和直观性方面还存在一些问题。为弥补现有方法的不足,利用DiamondView^TM荧光成像技术对有机充填处理的碧玺样品进行研究。结果显示,在DiamondView^TM下碧玺样品呈绿色或蓝色荧光,部分样品可观察到生长结构特征。分布于碧玺裂隙及凹坑内的有机充填物呈较强的蓝白色荧光,并与碧玺的荧光具有明显的差异和界限。利用DiamondView荧光图像分析,可以快速准确地识别充填物的位置及分布,也为碧玺在充填程度等方面的研究提供了新的思路。     

铅玻璃充填碧玺初探

利用常规宝石学测试、X射线荧光光谱仪（XRF）、激光诱导离解光谱仪（LIBS）、电子探针（EPMA）对近来在珠宝市场上的铅玻璃充填碧玺样品进行测试与分析,旨在探讨其鉴定特征。结果表明,该铅玻璃充填样品的充填特征不明显,与传统的有机物充填处理方法不同;X射线荧光光谱和激光诱导离解光谱的测试结果显示,该铅玻璃充填碧玺样品具有明显的Pb峰。铅玻璃充填碧玺样品中充填物的电子探针二次电子像及背散射电子像特征,可作为碧玺样品是否经过了铅玻璃充填的诊断性依据,其充填物的化学成分主要为Si和Pb,呈不规则斑块状分布于裂隙中。     

碧玺充填处理鉴定与充填程度分级研究

采用实验室常规检测方法和大型仪器测试技术(DiamondView~(TM)、红外光谱仪、激光拉曼光谱仪、X射线荧光光谱仪、电子探针、扫描电镜等),对充填处理碧玺的鉴定特征进行了深入的分析和研究。测试结果表明,市场上销售的经人工充填的碧玺中充填物主要为环氧树脂等高分子聚合物。经充填处理的碧玺,显微放大检查常可见充填物残余、气泡、流动构造等现象,裂隙出露表面处可见充填物与主体存在光泽差异。紫外荧光灯及DiamondView~(TM)下,充填物常沿裂隙或坑洞发出明显蓝白色荧光。红外光谱仪测试显示3 057cm~(-1),3 038cm~(-1),2 957cm~(-1),2 947cm~(-1),2 874cm~(-1),5 985cm~(-1),5 922cm~(-1),5 885cm~(-1)附近环氧树脂吸收峰。激光拉曼光谱仪测试显示1 112cm~(-1),1 185cm~(-1),1 608cm~(-1)组合的特征拉曼位移。扫描电镜测试中,充填物高分子聚合物在背散射电子像中为深灰色,面扫描测试显示充填处主要元素为碳(C),可指示有机充填物的存在。本文将充填处理单粒碧玺、珠串及群镶碧玺的充填程度与市场价值关系的研究成果及分级原则和方法进行了阐述。单粒碧玺中以充填裂隙的大小、形状、位置、数量、充填程度以及充填裂隙总和面积与样品最大截面积的占比,将其充填程度共划分为T0,T1,T2,T34个等级;珠串及群镶碧玺中以每一粒碧玺的充填等级,结合不同充填程度颗粒数量占整个样品颗粒数量的比例,将珠串及群镶碧玺共划分为TS0,TS1,TS2,TS34个等级。首次提出充填处理碧玺合格判定原则和定名表述形式。     

X射线能谱仪测定宝石和玉石成分及磁化率测试

用Ｘ射线能谱仪对一些宝石、玉石样品进行了成分分析，并测试了磁化率。样品中含铁、铬氧化物者磁化率偏大，碧玺、玛瑙、合成刚玉及月光石的磁化率为负，表现出抗磁性     

碧玺的充填处理

利用宝石显微镜、红外光谱仪、紫外-可见光谱仪等测试方法对一件充填处理的黄绿色碧玺样品进行测试研究,宝石显微镜下可见糖浆状流动构造,有时可见蓝色闪光;红外光谱见3056cm~(-1)处苯环的特征吸收峰,以及2965cm~(-1)、2925cm~(-1)CH_3、CH_2的反对称伸缩振动致和2872cm~(-1)附近CH_3、CH_2的对称伸缩振动,显示样品进行了环氧树脂的充填处理;紫外-可见光谱仪测试见绿色碧玺的红区普遍吸收。     

常见宝玉石材料的放射性研究

选取了市场交易量较大的代表性珠宝玉石品种,如金刚石、刚玉、碧玺、祖母绿、翡翠、珍珠、珊瑚等,利用低本底多道高纯锗伽马能谱仪对其进行核素分析,测试天然放射性核~(226)Ra、~(232)Th和~(40)K的比活度值,获得样品的放射性水平。测试结果表明所有样品的放射性比活度处于很低的水平,低于检测值37 Bq/g,处于安全限以下;内照指数I_(Ra)和外照指数I_γ均远远低于国家对建筑材料中放射性核素的限量;人工辐照过的宝石样品放射性活度高于大多数未经过辐照处理的宝玉石样品。     

埃塞俄比亚欧泊充填处理及鉴定特征研究

埃塞俄比亚WOLLO地区产出的欧泊品种丰富,但火欧泊和水欧泊不稳定,易因外界温度或水分变化形成较多裂纹,严重影响其稳定性及加工性能。因此,本实验对埃塞俄比亚WOLLO地区产出的多裂纹火欧泊、水欧泊样品进行了充填处理,并对充填前、后的样品进行了显微放大观察和红外光谱、相对密度、紫外荧光的测试及分析,总结出了有机充填欧泊的一些鉴定特征。测试及分析结果显示,在2800-3100cm叫范围内红外吸收峰为有机充填欧泊的主要鉴定特征,表面及内部显微充填特征、偏小的相对密度、裂隙处的蠕虫状及空洞缺陷处的斑块状强蓝白色荧光可作为辅助鉴定特征。从样品的充填及测试分析结果可见,埃塞俄比亚WOLLO地区产出欧泊的有机充填方案可行,比较明显的开放裂隙易被充填。     

碧玺自发极化效应的环境应用以及人体保健作用

碧玺是一种色彩丰富倍受青睐的宝石,同时也可以作为环境矿物用来治理环境.碧玺具独特的自发极化现象,具有表面电场,可以电解水、吸附带电离子、释放空气负离子.这些独特的性质赋予碧玺治理环境的用途,例如吸附污水中重金属离子、降解有极大分子污染物等.人体佩戴碧玺时,这种自发极化现象也会带来一定的保健功效,具有一定的电磁屏蔽效果,促进人体新陈代谢.     

表面接触角的测量及表面张力在宝玉石鉴定中的应用

表面张力是固体表面重要的物理化学参数之一,其大小与温度和界面两相物质的性质有关。基于Young方程的推导,使用接触角测量法计算固体表面张力已被广泛应用于表面科学和工程领域。宝玉石材料大多具有光洁的表面,在接触角测量的准确性方面较其他表面不均一的固体材料具有明显的技术优势。本文运用现代仪器(FTA200动态接触角测量仪)测量了15个天然和合成宝玉石品种(钻石、合成碳硅石、合成立方氧化锆、碧玺、托帕石、翡翠、琥珀等),以及经覆膜和充填2种处理方法的宝玉石样品(镀膜钻石、覆膜托帕石、覆膜翡翠、覆膜琥珀、充填碧玺)的表面接触角,并运用公式计算其表面张力。测试数据表明,不同品种宝玉石的接触角数值存在差异,如钻石的接触角值为56.68°,其仿制品立方氧化锆的接触角值为37.79°;覆膜处理与未经覆膜处理的天然宝玉石的接触角数值差异明显,如琥珀的接触角值为92.49°,覆膜琥珀的接触角值为66.49°;充填处理宝玉石接触角的测试由于控制液滴的大小受条件限制操作难度较大,测试结果不能准确表达为裂隙中充填物的接触角数值,故充填处理的宝石不宜采用此方法进行区分。研究表明,对于部分宝玉石品种和覆膜处理宝玉石,其表面接触角及表面张力数值差异显著,可以作为宝玉石品种的辅助鉴定依据;尤其是运用接触角的差异对于宝玉石鉴定具有较好的判别性,能够对不同品种的天然宝玉石与表面覆膜的宝玉石样品进行有效区分。与常规宝石检测方法(如红外光谱、折射率测量方法)对比,接触角测量方法具有测量准确、操作简便,不破坏样品的特点,符合宝玉石无损鉴定的基本原则,且能够安全快速地测量高折射率宝石,可以解决宝玉石表面覆膜等与表面物性相关的检测疑难问题。     

充填红宝石的充填特征观察及命名建议

通过显微镜下观察充填红宝石内外部的充填特征、次生玻璃的形态,结合在Diamond View^TM荧光成像仪下观察红宝石基底及次生玻璃体的发光情况,对红宝石中玻璃质材料充填的"量"进行了判断.将红宝石的充填程度分为轻微充填、中度充填、明显充填3等,建议对应定名为红宝石(备注可见轻微充填现象)、红宝石(备注可见中度充填现象)、充填处理红宝石.     

电气石红外光谱和红外辐射特性的研究

精确测试和研究了不同种属电气石的红外光谱特征及不同种属、不同温度条件下热处理电气石的红外辐射特性。结果表明：电气石具有高红外发射率的本质在于其晶体结构中的分子振动具红外活性;铁、镁电气石红外发射率相近,且都大于锂电气石的红外发射率;电气石热处理的温度与红外发射率之间存在一定的对应关系,随着热处理的温度的增加,红外发射率减小,当温度增大到800℃红外发射率达到最大值,超过900℃,电气石开始分解,红外发射率开始下降;电气石在室温下最大单色辐出度相应的波长为9~10μm 与绝对黑体9.72 μm 吻合较好,为良好的红外吸收与发射材料。     

熔融制样-X射线荧光光谱法测定电气石中12种主次量元素

电气石是一类含硼的铝硅酸盐矿物,化学成分复杂、化学稳定性强,不易湿法分解,B_2O_3含量较高,导致其主次量元素的同时测定存在一定困难。本文采用熔融法制样,建立了X射线荧光光谱法测定电气石Na_2O、MgO、Al_2O_3、SiO_2、P_2O_5、K_2O、CaO、TiO_2、V_2O_5、Cr_2O_3、MnO、TFe_2O_3等主次量元素的分析方法。样品与四硼酸锂-偏硼酸锂-氟化锂(质量比为4.5∶1∶0.4)混合熔剂的稀释比例为1∶10,消除了粒度效应和矿物效应;在缺少电气石标准物质的情况下,选择土壤、水系沉积物及多种类型的地质标准物质绘制校准曲线,利用含量与电气石类似的标准物质验证准确度,测定结果的相对标准偏差小于4.2%。采用所建方法测定四种不同类型电气石实际样品,测定值与经典化学法基本吻合。本方法解决了电气石不易湿法分解和硼的干扰问题,测定结果准确可靠,与其他方法相比操作简便,分析周期短。     

负离子粉体材料的超细化和表面改性研究

采用聚羧酸盐为表面改性剂,用玛瑙球为研磨介质,研究电气石矿物粉末的研磨改性工艺,优化了最佳的研磨工艺条件,并对湿法研磨改性的电气石粉末进行了粒度分析测试.红外光谱显示,研磨改性后的电气石粉末表面带有聚羧酸基团,可进一步增进电气石粉末与各种材料的相容性能.改性后电气石粉未的负离子释放量达600个/cm3.     

彩色电气石致色离子的化学状态研究

为探究不同颜色电气石中致色元素的化学状态及其化学环境,利用X射线光电子能谱方法对绿色调（墨绿色、蓝绿色、淡绿色）和粉红色调电气石样品进行分析。结果表明,绿色调和粉红色调电气石样品中均含有少量的过渡金属离子,如Fe,Mn,Ti,Cr,且不含Li和Be。不同颜色的电气石晶体中过渡金属阳离子的化学状态相同,且分别为Fe3＋,Mn4＋,Ti4＋,Cr3＋,但其与阴离子配位的环境有所差别。绿色调电气石样品中虽然Fe的质量分数有较大的差别,但均有部分Fe元素与F结合,即占据晶体结构中的Y位;粉红色电气石样品中,Fe离子没有与F形成配位,仅占据结构中的Z位。相反,在粉红色电气石样品中,Mn主要与F结合配位的方式存在,占据结构中的Y位,而绿色调电气石样品中大部分的Mn与O配位成键,只有少部分的Mn与F结合配位。由于Fe3＋,Mn4＋离子对之间电荷转移的可能性不大,故电气石的颜色可能主要由于d—d电子跃迁和氧与金属离子（O2--M）间电荷转移吸收引起,尤其是由于化学环境的差异（包括配位阴离子种类、杂质缺陷、结构畸变等）所引起。     

Changes in tourmaline composition during magmatic and hydrothermal processes leading to tin-ore deposition: The Cornubian Batholith,SW England

To investigate the potential of tourmaline as a geochemical monitor, a comprehensive dataset on major, minor and trace element concentrations as well as Fe³⁺/ΣFe ratios of tourmaline is presented. The dataset includes samples from five plutonic complexes related to diverse magmatic to hydrothermal stages of the Cornubian Batholith (SW England). Tourmaline composition found in barren and cassiterite-bearing samples include all three primary tourmaline groups and tourmaline species with the general endmembers schorl, dravite, elbaite, uvite, feruvite, foitite and Mg-foitite.Based on textures and compositions, it is possible to distinguish not only between late-magmatic and hydrothermal tourmaline, but also between several formation stages. Hence, tourmaline monitors late-magmatic processes and the partitioning of elements during exsolution of an aqueous phase. For example, in hydrothermal tourmaline Sn is strongly enriched, while Ti, Cr, V and Sc are depleted compared to late-magmatic tourmaline of the same sample. Several tourmaline generations that precipitated from magmatic fluids can be distinguished with differing major and minor elements and REE patterns depending on the composition of the melt from which they were expelled from. Strongly zoned tourmaline allows for unraveling the hydrothermal history of a distinct location including ore precipitation. The precipitation of SnO₂ in the study area was probably caused by mixing between acidic, reduced, Sn-bearing magmatic fluids and oxidized meteoric fluids, which is in agreement with London and Manning (1995) and Williamson et al. (2000). Hence, the ability of tourmaline composition to monitor changes in Sn concentration and redox conditions in hydrothermal fluids has potential as an exploration tool.     

Development and Re‐Evaluation of Tourmaline Reference Materials for In Situ Measurement of Boron δ Values by Secondary Ion Mass Spectrometry

Six tourmaline samples were investigated as potential reference materials (RMs) for boron isotope measurement by secondary ion mass spectrometry (SIMS). The tourmaline samples are chemically homogeneous and cover a compositional range of tourmaline supergroup minerals (primarily Fe, Mg and Li end‐members). Additionally, they have homogeneous boron delta values with intermediate precision values during SIMS analyses of less than 0.6‰ (2s). These samples were compared with four established tourmaline RMs, that is, schorl IAEA‐B‐4 and three Harvard tourmalines (schorl HS#112566, dravite HS#108796 and elbaite HS#98144). They were re‐evaluated for their major element and boron delta values using the same measurement procedure as the new tourmaline samples investigated. A discrepancy of about 1.5‰ in δ¹¹B was found between the previously published reference values for established RMs and the values determined in this study. Significant instrumental mass fractionation (IMF) of up to 8‰ in δ¹¹B was observed for schorl–dravite–elbaite solid solutions during SIMS analysis. Using the new reference values determined in this study, the IMF of the ten tourmaline samples can be modelled by a linear combination of the chemical parameters FeO + MnO, SiO₂ and F. The new tourmaline RMs, together with the four established RMs, extend the boron isotope analysis of tourmaline towards the Mg‐ and Al‐rich compositional range. Consequently, the in situ boron isotope ratio of many natural tourmalines can now be determined with an uncertainty of less than 0.8‰ (2s).     

新疆色带电气石的生长过程及颜色起因研究

本文以新疆阿尔泰山地区花岗伟晶岩中的色带电气石为重点,应用X射线透射形貌技术,揭示了光学显微镜无法查明的结构缺陷,结合晶体表面微形貌观察及包裹体研究,阐明了色带电气石晶体的形成过程和生长机理。同时运用吸收光谱、穆斯鲍尔谱、红外吸收、核磁共振等谱学方法,对照光谱及化学分析、电子探针分析结果,对阿尔泰不同颜色的电气石晶体,特别是玫瑰色的颜色起因作了较全面的讨论。     

Geological Evolution of Selected Granitic Pegmatites in Myanmar (Burma): Constraints from Regional Setting,Lithology, and Fluid-Inclusion Studies

Pegmatite deposits commonly occur in the 1500 km long, N-S-trending, tungstentin-bearing granitoid belt in Myanmar. Pegmatites are emplaced as veins and dikes that cut granitoid, migmatite, granitoid gneiss, gneiss, and schist. The pegmatite veins and dikes are mostly 2 to 5 meters wide and 30 to 150 meters long, and some are traceable over a distance of 300 meters.

The pegmatites are composed of quartz, orthoclase, albite, microcline microperthite, and muscovite, with minor biotite, tourmaline, beryl, garnet, topaz, lepidolite, magnetite, wolframite, cassiterite, and rare columbite. They are commonly zoned, feldspars and muscovite being more abundant in the center and quartz more common at the margin. The zoning pattern is rather distinct in the pegmatite body, where tourmaline is present. The light-colored felsic minerals are confined to the core zone and the dark-colored tourmaline crystals to the outer zone.

Numerous fluid inclusions have been found in quartz, topaz, and beryl. Most of the inclusions are rounded to elliptical, with a variable degree of liquid filling. All inclusions are aqueous, two-phase (liquid and vapor) inclusions with no daughter minerals. Homogenization temperatures of 173 fluid inclusions were measured in this study.

Geothermometric studies indicate that the pegmatites were formed over a homogeniza-tion temperature range of 230° to 410°C. Salinities of fluid inclusions in pegmatite minerals yielded from 1.0 to 10.8 NaCl equiv. wt‰. Topaz and quartz single crystals (several cm across) from the Sakangyi pegmatite provide an opportunity to extract the fluids trapped in these minerals. The Na/K ratios of the fluid inclusions in two topaz samples were 3.0 to 4.9, and those of two quartz samples were 2.9 to 10.5, suggesting the presence of substantial potassium in the pegmatite-forming fluids. In this study, evidence for phase separation of the pegmatite-forming fluids was not observed. The post-magmatic, hydrothermal fluids responsible for the pegmatite veins evidently emanated from cooling S-type granitoids, with which they are spatially associated.