Micro-Characteristic of "Briny" Root-Amber from Myanmar versus Beeswax-Amber from the Baltic Sea and Their Significance

Root-amber is one of the many varieties of amber from Myanmar, which is translucent to opaque with greasy lustre. Although the varied textures resemble tree roots, most amber lack of the regular tree patterns or annual rings. Thus, its pattern and origin often leave people with a sense of mystery. Preliminary analysis by scanning electron microscope revealed the presence of rounded spherical bubbles on the internal surface of root-amber from Myanmar, which varied in diameter from 0.1 μm to 1.5 μm, and the percentage of volume occupied by the bubbles was about 6% vol. A cubic halite crystal was found in almost every bubble inside. Features above suggest that the sap that formed the amber was once in a high temperature, high salinity environment, providing an important basis for the lagoon environment in which it was preserved. Such characteristics of bubbles in Myanmar root-amber share some similarities with Baltic beeswax-amber in terms of internal characteristics, but its transparency is significantly inferior to that of the latter. The diameter of the bubbles in Baltic white beeswax-amber ranges from 0.1 μm to 0.3 μm (pores account for 7% vol.), which is much smaller than the fine particles of 1.0 μm in diameter. One micron corresponds to 12 500 mesh, which reaches the particle size level of dust that presents white colour if the mineral is transparent. According to the principle that transparent mineral streaks are basically white, we believe that the white colour of the white beeswax amber is presented by the dense air bubbles of very small diameter (100-300 nm), not the real amber substance colour, and identify this as the white beeswax-amber phenomenon. The mechanism of coloration of root-amber from Myanmar is partially comparable to that of white beeswax-amber from Baltic, and its lower transparency may be attributed to the NaCl crystals that also contained inside. The discovery of small and dense (about 7% vol.) bubbles in white beeswax-amber also explains why white beeswax-amber is more readily able to release its rosin odor when it is rubbed, as these fine bubbles burst easily and release their odor when rubbed. The larger diameter (5.0-10.0 μm) and lower density of bubbles (about 1% vol.) in yellow beeswax-amber suggest that the bubbles only have a significant effect on its transparency and not on its body colour. Combining the above characteristics, it is suggested that it is probably more appropriate to change the name of Myanmar "root-amber" to "root beeswax-amber".