Egyptian Middle Kingdom copper: Analysis of a crucible from Buhen in the Petrie Museum

Abstract

The study of a well-preserved crucible fragment from the Middle Kingdom Egyptian fortress in Buhen in lower Nubia revealed the unexpected presence of numerous prills of very arsenic- and nickel-rich copper alloy in what looks like a smelting slag. Based on optical and scanning electron microscopy on a polished section, this paper discusses the potential metallurgical process that was carried out in this Middle Kingdom Egyptian type of crucible. Strongly reducing conditions preserved in the sample taken from near the low-sitting spout of the vessel indicate that it was likely used for smelting a very rich secondary copper-arsenic ore, rather than for the more oxidising refining of raw copper, or simple casting of copper-arsenic alloy. However, the evidence is not unambiguous, and these alternative interpretations are also discussed, considering the chronology and geographical context of the fortress near a known copper deposit in what was then the southern border of pharaonic Egypt.