摘要
采用电子探针(EPMA)、激光拉曼(Raman)光谱、~1H-核磁共振谱(~1H-NMR)和电子顺磁共振吸收谱(EPR)对四川石棉县的蛇纹石猫眼进行了测试分析。结果表明:蛇纹石猫眼的主要平均化学组成(质量分数)为SiO_243.56%,MgO 40.52%,FeO和Fe_2O_3混合物为2.14%,MnO0.05%。其中,致色离子主要为顺磁离子Fe^(3+)和Mn^(2+);蛇纹石猫眼Raman谱峰中3 700cm-1附近的—OH谱带分裂,并向低波数方向位移,主要与其不同颜色样品成分中Fe^(3+)和Mn^(2+)的含量、占位以及Fe^(3+)和Mn^(2+)对Mg^(2+)类质同象替换的程度有关;Fe^(3+)和Mn^(2+)同时占位于蛇纹石Mg—O(OH)八面体位置,随样品的颜色由浅黄绿色向暗褐绿色转变,Fe^(3+)和Mn^(2+)类质同象替代Mg^(2+)的程度增强,从而使Mg—O(OH)八面体部分分裂为((Fe^(3+)、Mn^(2+)),Mg^(2+))—O(OH)八面体。~1HNMR的测试结果也证实了这一点。
The cat eye effect is precious for serpentine cat’ s eye, which is very rare around the world, and is found previously only in California from U SA, namely, the California’ s cat’ s eye. Recently, this rare serpentine cat’s eye, with high value of appreciation and collection, was found in Shimian county of Sichuan province, southwest of China. In this paper, electron probe microanalysis （EPM A ） 、laser Raman、electron paramagnetism resonance spectra （EPR） and nuclear magnetic resonance spectra （NMR） were used to study the serpentine cat＇s eye samples from Sichuan province. The results indicate that the major average chemical compositions （ mass fraction） of the Sichuan serpentine cat’ s eye are SiO2 （43. 56%） , MgO（40. 52%） , Fe^3＋ Fe2O3 （2. 14%） and MnO（0. 05%）. The major color ions in serpentine cat’s eyes from Sichuan province are Fe^3＋ and Mn^2＋ . The Raman bands of -OH near 3 700 cm^-1 of serpentine cat＇s eyes from Sichuan show a clear difference with those of other ordinary serpentine samples： the Raman bands near 3 700 cm^-1 split off and shift to low wavenumbers, which is related to the content ofcolor ion, location of Fe3＋ and Mn^2＋ and the isomorphous substitution degree of Mg^2＋ with Fe^3＋ and Mnz＋. Fe^3＋ and Mnz＋ occupy the position of Mg^2＋ in the octahedral Mg -O（OH） of serpentine. The color of the samples changes from lower yellow-green to dark brown green with the increasing of the substitution degree of Mg^2＋. Therefore, the octahedral Mg-O（OH） of serpentine partly divides into octahedral [（Fe^3＋ ,Mn^2＋） ,Mg^2＋]-O（OH） as confirmed by ^1H-NMR.
作者
杜广鹏
卢保奇
彭景
王旭
DU Guang-peng;LU Bao -qi;PENG Jtng;WANG Xu(Jewelry Academy of Shanghai Jianqiao College,Shanghai 201306, China;School of Materials Science and Engineering , Shanghai University,Shanghai 200072, China;Institute of Geology and Geophysics , Chinese Academy o f Sciences,Beijing 100029, China)
出处
《华东理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2018年第1期70-74,共5页
Journal of East China University of Science and Technology
基金
国家自然科学基金(41572163)
