Archaeometallurgical investigation of copper metallurgy remains from the Fourth Dynasty settlement at Giza
Abstract
Austrian team, led by Karl Kromer, excavated in years 1971-1975 in the south-eastern part of the Giza necropolis, near the so called Southern Hill, with a view on Giza pyramids. Kromer realized that what he was excavating, was a settlement refuse, secondary or even tertiary deposition of discarded material culture from the Fourth Dynasty, from the reigns of Khufu and Khafra.
The finds were published few years after the excavation (Kromer 1978). The material was divided between Egyptian Museum, Cairo, and excavator.
This latter part of material is stored now in the Studiensammlung des Instituts für Urgeschichte und Historische Archäologie, Universität Wien, With a permission from the curator of the collection, Ass.-Prof. Mag.
Dr. Alois Stuppner, we have sampled a selection of the objects from Giza, remains of copper metallurgy (slags and crucible fragments), copper artefacts and their fragments, and a selection of faience objects.
We applied in this study a wide range of archaeometallurgical methods to the set of almost 40 samples. Selected copper alloy artefacts have been studied by metallographic methods in combination with microhardness tests and SEM/EDS analysis.
Fragment of vitrified crucible, slags, and copper alloy prills were analysed in the form of cross sections by methods of optical microscopy, SEM/EDS and WDS and µXRD. Lead isotope analyses carried out using a MC-ICP-MS spectrometer and neutron activation analysis of trace elements composition of copper alloy objects and copper alloy prills were applied in order to better understand the geographic provenance of the copper ores used.
In this paper, we would like to discuss the results and preliminary interpretation of the data. Analysed copper alloy tools were made from alloy of arsenical copper with 0.7 to 5.3 weight percent of arsenic and their hardness ranges between 65 and 162 HV units.
Fragment of vitrified crucible and samples of slags contain copper and arsenical copper prills rich in arsenic and also iron and antimony, incorporated in the slag phases formed by fayalite, wüstite and amorphous glassy phase and exceptionally also by quartz and copper/iron sulphides. This finding confirms the active remelting and casting operations and, most likely, the alloying of copper with arsenic at the settlement near the Giza necropolis.
Trace elements composition and lead isotope ratios of arsenical copper tools and arsenical copper prills are, with a few exceptions, very homogeneous and point out to the provenance in the Eastern Desert of Egypt and/or Sinai Peninsula, similarly to others recently published data of copper alloy artefacts from the Old Kingdom (Kmošek et al. 2018; Rademakers et al. 2018). Unexpected addition and comparison for the material in Vienna has been excavated recently.
American mission of AERA organization (lead by Mark Lehner) at Giza worked again at the place of Kromer's excavations and it gained new material, also of archaeometallurgical character. These finds will need to be studied in Egypt, but material from Vienna provides valuable comparative information.