Fingerprint Characteristic and Origin Traceability of Amber Artefacts——Application in Archaeological Amber from Han Dynasty

Han Dynasty was an important period in the development of ancient Chinese amber art, during which the quantity and shape of unearthed amber reached a new height. However, the deteriorated and oxidised skin of the excavated amber poses a significant challenge to non-destructive spectroscopy testing and result analysis. The article selected 113 pieces of rough amber samples with different degrees of oxidation from the Baltic region, Myanmar, and Fushun, China, were selected as reference samples to explore the specific effects of oxidation and erosion on the spectral characteristics of amber origin traceability. Microscopic observation and infrared spectroscopy were used to collect the characteristics of amber from the Baltic region, Myanmar, and Fushun before and after oxidation. The results showed that infrared spectroscopy could effectively distinguish amber from the three origins for unoxidised and slightly oxidised amber. After processing the infrared data of the rough amber samples, infrared database for the origin traceability of unearthed amber was established, and an origin tracing process based on spectral peak identification was developed. An amber origin tracing model was established using pattern recognition analysis, which achieved a good identification effect for 113 pieces of amber samples, with an accuracy rate of 96.5%. Origin tracing models applicable to amber unearthed from two different regions were separately established using the rough amber materials?infrared database. The classification results of the models indicated that the amber unearthed from the Haihun Marquis?Tomb all came from Myanmar, while 3 pieces of amber unearthed from Han Dynasty tombs in Hunan Province originated from the Baltic region and one from Myanmar. Therefore, it can be seen that amber both from the Baltic region and Myanmar were introduced into China and widely used during the Han Dynasty.