福建云霄石榴子石宝石矿物学特征
Gem mineralogy characteristics of Yunxiao garnet,Fujian,China
陈星韵 1张良 2王豪帅 3张瑞锐 3孙思辰4
作者信息
- 1. 中国地质大学(北京)珠宝学院,北京 100083
- 2. 中国地质大学(北京)珠宝学院,北京 100083;中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京 100083
- 3. 中国地质大学(北京)地球科学与资源学院,北京 100083
- 4. 福建省地质矿产勘查开发局,福建福州 350003
- 折叠
摘要
福建云霄是我国重要的宝石级石榴子石产地,然而该区石榴子石的致色机理不清,制约了对其形成机制的理解及后续开发利用.本文选取7件福建云霄橙黄-橙红色石榴子石样品,利用傅立叶红外光谱、紫外-可见光光谱和拉曼光谱分析其谱学特征,使用电子探针及激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)分析限定其主量、微量元素组成.结果表明云霄石榴子石主要为锰铝榴石,其颜色主要与二价锰(Mn2+)和铁离子(Fe2+)对可见光的吸收有关,Mn2+导致其主体呈橙色,少量Fe2+控制其橙红色调,微量Ti4+使其呈褐色调.福建云霄石榴子石样品核部锰含量相对较低而铁、镁含量较高,锰元素含量由核部向边部逐渐升高,且具有重稀土元素富集、轻稀土元素亏损的左倾配分模式和Eu负异常,表明其形成于岩浆结晶作用晚期.
Abstract
Yunxiao is a significant producing area of gem-quality garnet in China.However,the color origin of gar-net in this area remains ambiguous,which restricts the understanding of their formation mechanism and subsequent exploitation.In this paper,7 samples of orange-yellow-orange-red garnet from Yunxiao,Fujian were selected,and the spectral characteristics of the samples were analyzed by Fourier infrared spectrum,UV-visible spectrum and Ra-man spectrum,and the characteristics of main and trace elements were defined by electron probe(EPMA)and la-ser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS)analysis.It is concluded that the color of the garnet is predominantly influenced by the absorption of visible light by Mn2+and Fe2+.Mn2+dictates the yellow tone of the garnet,while a minor amount of Fe2+governs the orange-red tone.Additionally,a trace amount of Ti4+imparts a brownish appearance to the garnet.The samples exhibited a relatively low manganese content and high iron and magnesium content in their core,a gradual increase in manganese content from the core to the rim.The samples also displayed a left-leaning partition pattern,with an enrichment of heavy rare earth elements and a deficit of light rare earth elements.Europium(Eu)showed a negative anomaly.These findings suggest that the garnets from Yunxiao,Fujian were formed during magmatic processes and are products of late-stage magmatic crystallization.
关键词
石榴子石/宝石学特征/矿物光谱/致色机理/福建云霄Key words
garnet/gemological characteristics/mineral spectroscopy/color mechanism/Yunxiao,Fujian Prov-ince引用本文复制引用
基金项目
国家重点研发计划(2019YFA0708603)
高等学校学科创新引智计划(111计划)(BP0719021)
出版年
2024
国家科技期刊平台
NSTL
万方数据