缅甸根珀的宝石学特征

Gemmological Characteristic of Root Amber from Myanmar

  • 摘要: 缅甸是重要的琥珀产区,其产出琥珀品种繁多,根珀是其中一个特殊品种,含有复杂多样的包裹体。通过宝石常规测试以及红外光谱、拉曼光谱、扫描电子显微镜及能谱等测试对缅甸根珀的宝石学特征、内部结构及内含物成分进行了分析。结果表明,缅甸根珀平均相对密度为1.09,折射率为1.52~1.53(点测),长波紫外光下发中等至强的白色—蓝白色—蓝色荧光,短波紫外光下发弱至强的白色—蓝白色荧光。红外光谱测试结果显示,根珀的基体部分(琥珀部分)具有和其它缅甸琥珀品种一致的特征红外吸收峰。拉曼光谱显示,根珀的基体部分成熟度达到琥珀,并非柯巴树脂。扫描电子显微镜结果显示,根珀基体部分的片层状结构不明显,说明部分质地致密。拉曼光谱和扫描电子显微镜结合能谱仪测试表明,缅甸根珀包裹体种类复杂,含有微晶球体、气泡、空管、矿物包裹体和植物碎屑,其中,矿物包裹体为方解石、黄铁矿、磷灰石和硅酸盐矿物。

     

    Abstract: Myanmar is an important amber producing region, which produces numerous varieties of amber. Root amber is one of the special kinds which has varied and complicated inclusions. This paper applies conventional geommological tests, FTIR spectrum, Raman spectrum, SEM with energy spectrum and other methods to test and analyze the gemmological characteristics, internal structure and inclusions of root amber from Myanmar. Testing results show that the average relative density of root amber is 1.09 and the refractive index extent is 1.52 to 1.53(point measurement). In addition, the fluorescence of root amber presents middle to strong white or bulish white or blue colour under long wave ultraviolet light and weak to strong white or bulish white colour under short wave ultraviolet light. The FTIR spectrum indicates that the characteristic vibration peaks of matrix in root amber are consistent with the other ambers from Myanmar.The Raman spectrum shows that the matrix of the root amber is more mature than copal resin. The SEM testing results show that layered structure in the matrix part is not apparent, which concludes that the matrix in root amber has compact structure. The tesing results of Raman spectrum and SEM combined with energy spectrum indicate varied and complicated such as in root amber from Myanmar, include microcrystalline spheres, bubbles, blank pipes, mineral inclusions and floristic clastics. Mineral inclusions such as calcite, pyrite, apatite and silicate have been detected in the experiments.

     

/

返回文章
返回