墨西哥“琥珀色”托帕石及纤维状包裹体研究

Study of "amber" topaz and fibrous inclusions from Mexico

文章研究的9颗“琥珀色”托帕石产自墨西哥,晶体形态规则,整体颜色以橙黄至褐黄色为主,晶体大小在20~35 mm之间。部分常规宝石学特征为折射率值1.61~1.62的范围,长波紫外光下弱橙黄色荧光,中等强度三色性,镜下可见柱面发育密集的生长丘,内部含有丰富的弯曲纤维状矿物包裹体,拉曼光谱揭示其为赤铁矿包裹体。通过红外光谱分析得知,该类托帕石为富F型的托帕石,含OH-极少。

The 9 pieces of"amber"topaz studied in this paper are from Mexico,these topazes have regular crystal morphology,the colors are mainly orange-yellow to brownish-yellow,and the sizes are between 20 mm-35 mm.Through some conventional gemological tests,the range of refractive index is 1.61-1.62,weak orange-yellow fluorescence under LW ultraviolet light,moderate trichroism.Densely developed growth hillocks and dense curved fibrous mineral inclusions are observed under the Gem microscope.Raman spectroscopy reveal the kind of fibrous inclusion is hematite.Further testing by Infrared spectroscopy shows that the samples are F-type topaz with very little OH-content.