The Origin of the Archaeological Amber in Japan —Studies by Infrared Spectra—

Abstract

There are many archaeological amber objects found in Europe, and some attempts have been made to determine the provenance of these ambers. In Japan, a few beads have been excavated from old tomb, but the provenances of these ambers are not known. In the present work, the authors investigated several methods of determination of provenance of Japanese amber artifacts, using scientific techniques such as elementary analyses, infrared spectroscopy and measurement of the melting point. In the study, the geological standard samples, offerd by some museums and laboratories were used. They were collected from main amber sources such as Kuji, Choshi, Mizunami and Kobe in Japan and Fushun in China. Other samples of unknown origin were; those from Todaijiyama Old Tomb in Nara prefecture and those from Nagaike Old Tomb in Kyoto prefecture. The results of elementary analyses are the following, in the archaeological samples, C: H: O =20~22: 30~34: 4 and in the geological standard samples, C: H: O=25~184: 52~302: 4; here it is interesting to see that the archaeological samples show much less variation in composition with the geological samples. Each infrared spectrum of these ambers shows a characteristic pattern depending upon its provenance; our samples vary considerably in color and were obtained in different ways, but nevertheless, the spectra of amber from the same provenance show the same pattern. Therefore the authors strongly suggest that the best means of determination of the provenance of amber artifacts is to record the full spectrum of infrared absorption and to compare with that of standard samples. The archaeological amber samples from Todaijiyama Old Tomb and Nagaike Old Tomb were found, to have the same provenance; Kuji in Iwate prefecture. From there results, it is concluded that there were trade links between Kinki district and Tohoku district the sixth century A. D. © 1974, The Chemical Society of Japan. All rights reserved.