Comparison and Identification of Reconstructed Ambers Produced in Different Periods Based on Micro-structures

With the increasing development of the manufacturing technology of reconstructed ambers, more and more reconstructed ambers produced in different periods appear in the jewelry market.In order to correctly identify reconstructed ambers, based on the previous studies and research results of NGTC in recent years, this paper investigates and illustrates the micro-structures of reconstructed ambers by using imaging techniques of magnification, crossed polarization, and UV fluorescence.The results show that the traditional reconstructed ambers produced in early period display obvious blood-red streak-like structures, as well as fluorescence features.For the ambers produced recently, the characteristics revealed by magnification and polarization testing are not clear, due to a series of post-processing which could have covered the original features of reconstructed amber.However, some features, such as flaky cracks distributed along the blood-red streaks, flowing granulated sugar-like structure and so on, could be seen by using strong transmitted illumination technique.The reconstructed ambers produced in different periods could be correctly identified by detailed microscopic observation.