Gemmological Characteristic of Root Amber from Myanmar

Myanmar's root amber is an opaque amber that has been formed after a long period of time. During the formation, the entry of calcite formed some special textures of the root amber. At present, there are few reports about the geological occurrence, category, microstructure and mineral components of this kind of amber in the field. Some conventional gemmological methods, gem microscope observation, X-ray fluorescence, infrared spectroscopy, and Raman spectroscopy tests were conducted. The results show that the root ambers from Myanmar under the long wave of ultraviolet fluorescent lamps have a light yellow, khaki-yellow fluorescence, while generally no fluorescence under short-wave. It is different from the common blue-white fluorescence of amber and beeswax from Myanmar. Under the microscope, root amber from Myanmar has characteristic textures such as tree ring patterns and flow patterns, containing gold pyrite inclusions, pulse-like quartz monocrystalline particles, and strips of cryptocrystalline chalcedony inclusions and some samples have a brownish red, black filamentous material distribution. Those microscopic structure phenomena can be used as one of the basis for the identification of root amber from Myanmar. According to the analysis of spectral characteristics and chemical compositions, root amber from Myanmar is an amorphous biological fossil and the main component is amber, containing a large amount of calcite, a small amount of pyrite, quartz monocrystalline particles, cryptocrystalline chalcedony and sulfides. In addition to the elements C, O, and H, the root amber from Myanmar also contain elements such as S, Ca, Fe, Si, Zn, which are consistent with their mineral components. The large number of S element in root ambers from Myanmar is consistent with its very serious vulcanized surface. Besides, S element can also form pyrite(FeS₂).