岩石矿物学杂志2024，Vol.43Issue(3)：619-629,11.DOI:10.20086/j.cnki.yskw.2024.0310
尼日利亚锌尖晶石的宝石矿物学及包裹体特征研究
Gem mineralogy and inclusion characteristics of gahnite from Nigeria
摘要
Abstract
The conventional gemological properties,chemical composition,crystal structure,and inclusions compo-sition and characteristics of the Nigerian gahnite were analyzed in depth by conventional gemological testing,elec-tron probe,single crystal X-ray diffraction,and Raman spectroscopy.The gahnite exhibits well-preserved octahe-dral crystal morphology,strong vitreous luster,and semi-transparency,with a relative density ranging from 4.48 to 4.61 and a refractive index of 1.792 to 1.794,displaying inert fluorescence under ultraviolet light.The electron probe analysis determined its chemical formula as Zn(0.87～0.92)Fe(0.06～0.07)Al(1.98～2.01)O4.Single-crystal X-ray diffrac-tion revealed a cubic crystal system with space group Fd3m,lattice parameter a=8.089(2)Å,tetrahedral bond length T—O=1.953(4)Å,and octahedral bond length M—O=1.912 9(19)Å.Characteristic Raman absorption peaks for gahnite were identified at 418 cm-1 and 659 cm-1,corresponding to the Eg mode and high-frequency T2g(3)mode,respectively.Raman spectroscopy of inclusions confirmed the presence of various minerals in gahnite,including sphalerite,albite,muscovite,quartz,beryl,zircon,and phenacite.Combined with previous studies,it is believed that gahnite in Nigeria is formed in granite-pegmatite rich in Li,Cs,Rb,Be and Ta.关键词
锌尖晶石/宝石学/矿物学/包裹体特征Key words
gahnite/gemology/mineralogy/inclusion characteristics分类
天文与地球科学引用本文复制引用
陈仪方,金雪萍,刘子琪,周征宇,郑浚豪,管琪韵,陈琦..尼日利亚锌尖晶石的宝石矿物学及包裹体特征研究[J].岩石矿物学杂志,2024,43(3):619-629,11.基金项目
National Natural Science Foundation of China(49772096) （49772096）
Project of Shanghai Science and Tech-nology Commission(18DZ2281300) 国家自然科学基金项目(49772096) （18DZ2281300）
上海市科委项目(18DZ2281300) （18DZ2281300）
