缅甸琥珀“留光”效应和变色效应的谱学特征

The Spectrum Characteristic Research of Color Change Effect and “Light Tarry Effect” Amber from Burma

近年有发现缅甸琥珀具有特殊的变色和"留光"效应,因其品种的稀有和珍贵,具有极高的商业价值和研究价值,而关于此类缅甸琥珀的颜色成因研究未见相关报道。笔者对缅甸变色效应琥珀、"留光"效应琥珀以及不变色普通琥珀样品进行了宝石学常规测试包括:X射线荧光光谱仪(XRF)、 X射线粉晶衍射仪(XRD)、红外光谱仪、紫外可见分光光度计的测试,以探索缅甸"留光"效应和变色效应琥珀与普通琥珀的差异性,为缅甸琥珀"留光"效应和变色效应的颜色成因机理提供依据。研究结果如下;(1)XRF物质成分分析显示:缅甸"留光"效应琥珀含有较高的硫(S)是普通琥珀的4倍之多,较高的钙(Ca)元素含量接近普通琥珀含量的6倍;(2)XRD物质结构分析显示:缅甸变色效应琥珀在15~0有尖锐的特征峰,而普通琥珀没有;(3)紫外光谱图中:缅甸变色效应琥珀在210和447 nm有独特的吸收峰,其他种类琥珀没有;(4)五颗琥珀样品的红外光谱吸收峰相同,显示其来自同一个产地缅甸。具有特殊光学效应的琥珀可能与缅甸琥珀形成的地层温压环境和地质年代有关,由于氧化程度高埋藏时间长,导致某些缅甸琥珀内部微结构以及微量杂质元素发生变化,以致出现一系列的特殊光学效应。

In recent years, the special color change effect and "light tarry effect" Amber from Burma have been found, and because of precious and rare, those special optical effect Burma Amber have high commercial value and research value. The formation mechanism of color change effect, "light tarry effect" and common Burma amber were studied by using standard gemological methods, modern testing method as: X-ray fluorescence spectrometer(XRF),X-ray powder diffraction(XRD), Fourier infrared absorption spectroscopy(FTIR), Ultraviolet-Visible spectrometer(UV-VIS) to obtain the gemology and spectra characterization of samples.(1) XRF result showed that "light tarry effect" Burma Amber contain high element S which is over 4 times common Burma Amber’s, and contain high element Ca which is 6 times common Burma Amber’s;(2) The UV-VIS result showed that the color change effect Burma Amber have 210 and 447 nm absorption in the UV area;(3) XRD result showed the color change effect Burma Amber have the 15~0 sharp absorption peaks;(4) Because the five samples are from the same origin which is the Burma,the infrared absorption spectra are similar from all of the samples that have no obvious difference. Conclusion: The above special optical effect Burma amber maybe relate to the temperature and pressure of the stratum which formed the Burma Amber, also relate to the geological timescale. Because of high degree oxidation and the fact that the Burma Amber were founded deeper in the ground, the internal micro structure and trace substance composition have changed, so that special optical effects of some Burma amber arised.