Ancient Greek slags of Zagora

Zagora is a complete, undisturbed Early Iron Age Aegean settlement from the 9th-8th centuries BC. Archaeological survey and excavation at the site has found an abundance of metallurgical slag, waste material from the metalworking industry. Iron production occurred in Greece for a century or two before the occupation of the site but limited work has been done on Greek metalworking from this period.

Ms Ivana Vetta, a postgraduate student is using scanning electron microscopy coupled with elemental and crystal orientation analyses in the AMMRF (now Microscopy Australia) at the University of Sydney to uncover the unique microstructure of the slag. This in turn provides information about the pyro-technological skills and processes used by the ancient smiths.

From the outside, the slag appears simply as a lump of mildly magnetic rock but inside the structures are highly variable and contain a complex mixture of iron-rich minerals. The presence and structure of the minerals fayalite and wustite in the Zagora slags indicates that the slags are most likely to have come from the iron smithing phase. It also reveals that a lot of iron was lost in the slag, indicating a very inefficient process for iron production at this stage of history. Analysis also revealed the presence of quartz and silicate minerals, suggesting that sand may have been used as a flux to help purify the iron prior to smithing.

Ms Vetta’s results are combining with other archaeological evidence to uncover ancient metalworking processes and how they connect to the wider civilisation.

Ms Vetta acknowledges the permission of the Hellenic Ministry of Culture under the Aegis of the Australian Archaeological Institute at Athens (AAIA).