A compositional and structural study of a prehistoric Egyptian iron meteorite bead

D Johnson1, M M Grady1, T Lowe2, J Tyldesley2
1The Open University, UK, 2University of Manchester, UK

One of the earliest examples of iron used by man was discovered in a prehistoric Egyptian cemetery in the form of 9 beads. The Gerzeh site, 40 miles south of Cairo, was excavated in 1911 where over 300 grave pits dating from around 3300 BCE were discovered. Some of these graves contained rare and precious materials, two graves, Tombs 67 and 133 were found to contain iron beads that contained significant levels of nickel, which led to identification of meteoritic origin.

Our study is intended as an illustration of the non-destructive analysis of an intact artefact, allowing a better understanding of this rare and precious sample. Optical imaging, electron microscopy, EDS and X-ray micro CT analysis were performed to define the structure and chemistry of the bead. 

A complex weathering pattern was revealed composed of multiple layers of oxides and metal. The outer oxide layer incorporating rounded quartz grains that originated in the grave pit, which was filled with sand. Patches of the oxidized areas have partially fallen away, allowing direct examination of underlying regions in which small areas of metal were observed. The tubular bead structure interior was also found to be filled with the flax plant fibers originally used to string the beads together.

Acknowledgements: we would like to thank Dr Karen Exell, Curator of Egypt and the Sudan, at the Manchester Museum, for the loan of Gerzeh bead, accession number: 5303