EMF - Previous Meetings

Study of black layer on ancient Chinese bronzes

Quanyu Wang, John Merkel

A large number of bronze objects were unearthed from the nobility tombs of the Jin State, one of the vast states during 1027-450BC at Qucun site, Shanxi, China from 1992 to 1994. Bronze fragments from the tombs are examined by macroscopic observation, metallographic observation, XRD analysis and SEM/microprobe analysis.

The most interest is that a black layer is present on the surface of the original metal for some of these bronzes. The question has been raised: is the black layer intentional patination or natural corrosion product? What was the technique if it was an intentional patination? How did it form if it was from the corrosion process. This paper try to give an answer to this question.