moment correspondant à leur dernière fonte et ainsi de vérifier leur ancienneté. Dans cet article nous présentons une étude systématique et quantitative de l’He, de l’U et du Th dans un large nombre d’objets d’or anciens et modernes.
spectrométrie de masse
Authenticating archaeological gold objects is a major problem, as gold is probably the most difficult material in terms of detecting modern forgeries. In 1996 we published the results of the study of faked and genuine gold crystals from the Santa Elena gold mine in Venezuela, and demonstrated that the U/Th – He dating method is a powerful tool for detecting forgeries among gold objects. U and Th decay by emitting He atoms that remain stored in gold. By measuring U, Th, and He, the time when the He trapping process started can be determined. In the 1996 publication we also mentioned that the same method can be applied to ancient gold objects, in order to determine the time when they experienced their last melting process and, thus, to verify their antiquity. In the present work we report on a systematic and quantitative study of He, U, and Th in a large number of ancient and modern gold objects.