Gold parting, iridium and provenance of ancient silver: A reply to Pernicka

We present a detailed response to Professor Pernicka's critique of our paper entitled “Iridium to provenance ancient silver”. We have concluded that Pernicka's hypothesis, which suggests that elevated levels of iridium in ancient silver artefacts is a consequence of silver deriving from the cementation (parting) process, does not account for the available evidence and that his critiques of the analyses we presented seem misplaced. We offer a simpler solution and show that the structure of our transformed data is founded on logical reasoning which is borne out by the empirical results. Essentially, this response supports our view reported in the original paper that the variation in iridium in ancient silver is largely geological rather than a consequence of de-silvering gold.