Abstract:
Amber is an organic gem, which has important research value in gemmology, geology, paleontology and other disciplines. Previous studies on amber mainly focused on gemmological and spectral characteristics. In terms of micro-morphology, only a few achievements were made in Baltic honey wax and Dominican amber. Amber from Myanmar, as one of the important sources of amber, has great exploration space.In this paper, the microstructure characteristics of amber from Myanmar were studied by using infrared spectra and scanning electron microscope. Data of the amber from Myanmar has been calculated and analyzed, and the relationship of the microscopic characteristics, the quality and the density of beeswax were summarized. The formation reason of the structure of root amber from Myanmar and the formation mechanism of rubbery looks of brown amber from Myanmar were deduced. The results showed that root amber has a spongy and fibrous basis that contains gas bubbles with anomalous elliptical shape. The structure of root amber from Myanmar can be divided into two categories: Tight and loose.In addition, tight root amber contains uniformly distributed curved tubes ranging from 10 to 30
μm diameters, along which bubbles were gathered; While the size of bubbles in loose rough root amber was different, and the diameter of small bubbles was 1 to 2
μm, and the diameter of big bubbles was up to 11
μm. The conclusions can be drawn from the experimental results: (1) The proportion of bubble area and the uniformity of bubble distribution are positively correlated with the dense structure of root amber, that is, the larger the bubble area ratio, the smaller the bubble diameter, the more uniform the distribution, the denser the root Perot structure, and vice versa; (2) According to the shape, size and distribution characteristics of bubbles, the bubble in root amber of Myanmar can be inferred to be the self-contained volatile components of terpenes; (3) It can be speculated that the formation of bubbles in root amber is related to the volatile components such as terpenes and succinic acid carried by the resin itself, while the formation of empty tubes has two inferences. One is suspected to be the escape channel of volatile components. An alternative explanation is that the tubes are small cracks formed during the evolution of the amber; (4) It is first discovered that the typical crimson punctate inclusions of amber from Myanmar, and the scaly structure of such inclusions is significantly different from the ambient amber’s laminated structure,which can be inferred that the typical inclusions are probably related to some specific substances of the ingredients, especially the volatile substances. The reason why the crimson punctate inclusions can form a flow-like pattern has something to do with the directional escape of volatile compositions.