越南Luc Yen矿区尖晶石常规宝石学及内含物特征研究

本文使用折射仪、荧光光谱仪、显微镜、拉曼光谱仪等多种测试仪器,对越南Luc Yen地区的尖晶石样品进行了常规宝石学特征及内含物的成分研究,为其产地鉴别提供理论依据。研究结果显示,越南Luc Yen地区尖晶石的折射率范围主要为1.716~1.718,在长波紫外光照射下大部分为弱~强的浅橙~红色荧光,短波紫外光下大部分为荧光惰性;样品相对密度约为3.63~3.98;显微观察可见固相包裹体、管状气液包裹体、网格状包裹体等包裹体,经拉曼光谱测试可确认的包裹体种类有八面体负晶包裹体、硬水铝石和CO2的拉长扁平负晶、金红石、磷灰石、锆石、方解石、阳起石、白云石、金云母、歪长石。

巴基斯坦橄榄石宝石学及矿物谱学特征研究

采用常规宝石学仪器并结合电子探针、激光剥蚀电感耦合等离子体质谱仪、(显微)红外光谱仪、紫外-可见吸收光谱以及拉曼光谱仪等测试方法,对巴基斯坦橄榄石进行了常规宝石学、化学成分和谱学特征等研究,并探讨了其产地鉴别方法和依据。结果表明,巴基斯坦橄榄石含有针状"硼镁铁矿-硼铁矿"、点状磁铁矿等特征矿物包裹体组合;与美国、中国、埃塞俄比亚、越南、马达加斯加等地所产的橄榄石相比,巴基斯坦橄榄石的微量化学元素组成相对富Li、B、Sc,贫Zn、Cu,同时V/Sc值偏低;巴基斯坦橄榄石红外吸收光谱中普遍存在的3580 cm-1附近吸收谱带与[Si]=(4H)_(Si)^(X)替代机制有关,指示其晶体中含有一定量的结构水;紫外-可见吸收光谱中的380、450、490、635 nm附近强吸收峰分别与O^(2)-→Fe^(3+)电荷转移带,Fe^(3+)的^(6)A1→^(4)A1+^(4)E(^(4)G)电子跃迁和Fe^(2+)的^(5)T_(2g)→^(3)T_(2g)、^(5)T_(2g)→^(3)T_(1g)电子跃迁有关。综合分析认为,包裹体、微量化学成分和结构水致红外吸收谱带特征组合可视为巴基斯坦橄榄石的产地鉴别依据。

Gemological-Mineralogical Characteristic of Spinels from Sri Lanka

Detailed mineralogical and gemological records were conducted on 340 unheated spinels from the Horana, Eheliyagoda, Ratnapura, and Okkampatiya mining areas in Sri Lanka. The color of Sri Lankan spinel varies greatly: in addition to the mainstream pink to purple pink, green and blue can also be seen. Compared with spinel from other regions such as Myanmar, Vietnam, and Tanzania, Sri Lanka's spinel has more abundant inclusions: several mining areas generally have inclusions such as dolomite, apatite, zircon, and chondrodite. Minerals such as graphite and forsterite are also found in spinel produced in the Horana region;graphite and rutile have been found in spinel produced in the Okkamptiya region. Partially healed fissures are most common in spinel in the Okkampatiya mining area;Unlike Vietnamese spinel, dislocations and growth structures are almost absent in Sri Lankan spinel. The LA-ICP-MS analysis results showed that there were no significant differences among the mining areas. LA-ICP-MS analysis of 5 Sri Lankan cobalt blue spinels showed a variation of 11 to 120 ppm in this chromogenic element. The UV visible absorption spectrum results show that Sri Lankan spinel has a combination spectra with variable ratios of the spectral components Cr 3+ , V 3+ and Fe 2+ from pink to red, orange, purple to purple, and blue-green. The results of infrared spectroscopy and laser Raman spectroscopy analysis showed that all samples showed no indications for heat treatment.

未处理、热处理与扩散处理橙色和粉橙色蓝宝石的颜色成因

总结了未处理、热处理和Be扩散处理的黄色—红色蓝宝石的颜色及其成因。综述了蓝宝石色心的主要类型。对热不稳定的黄色和橙色色心的性质与高温热处理或由Be扩散处理产生的热稳定橙色色心的特征进行了对比研究。对橙色色心形成的一些模式进行了详细描述和讨论, 这些模式是由 H ger(2001)和 Emmett等(2003)提出、根据样品中微量元素含量建立的。两个模式都是基于微量元素 Mg—Fe—Ti和(Be+Mg)—Fe—Ti三角图解建立的。对来自斯里兰卡的未处理和热处理帕帕拉恰蓝宝石的颜色成因与来自马达加斯加 Ilakaka和坦桑尼亚Songea的Be扩散处理蓝宝石的颜色成因进行了对比。处理与未处理蓝宝石颜色的巨大差异是由样品中的Fe和V的含量差异以及色心的丰度造成的。