Determination of provenance and species of Japanese Jōmon lacquer by pyrolysis-gas chromatography/mass spectrometry and 87Sr/86Sr isotope ratio

One piece of Japanese Jōmon period lacquerware from the Yachi Relic in Niigata Prefecture and four pieces from the Shimoyakebe Relic in Tokyo of Japan were first analyzed by Py-GC/MS to determine the lacquer species, and secondly the strontium (87Sr/86Sr) isotope ratio was analyzed to examine the provenance of the lacquer. Compared with the pyrolysis products of standard lacquers, the results showed that all the original objects were coated by sap that was tapped from a Toxicodendron vernicifluum lacquer tree. The 87Sr/86Sr isotope ratios were 0.7056 at Yachi and an average 0.7052 at Shimoyakebe; both are lower than 0.71, the borderline (=0.71) between the Chinese mainland (>0.71) and Japanese islands (<0.71). Thus, all five Jōmon lacquerwares were coated with lacquer sap tapped from T. vernicifluum lacquer tree grown in the Japanese islands.