The recent reanalysis of metallurgical remains from the archaeological site of Kvemo Bolnisi in southern Georgia has uncovered groundbreaking insights into ancient metalworking practices. This 3000-year-old smelting workshop was originally examined in the 1950s, where excavators discovered significant piles of hematite (an iron oxide mineral) and slag (a byproduct of metal production). Initially, these findings led researchers to believe that Kvemo Bolnisi was an early site for iron smelting. However, new research has challenged this assumption.
Recent studies indicate that the ancient workers at Kvemo Bolnisi were not primarily smelting iron, but rather copper. They utilized iron oxide as a flux, a substance that aids in the melting process and enhances the yield of copper. This revelation supports a long-debated theory suggesting that the origins of iron usage can be traced back to the practices of copper smelters. The evidence points to early copper metalworkers experimenting with iron-bearing materials in their furnaces, marking a pivotal step towards the eventual development of iron metallurgy.
The Iron Age signifies a major turning point in the history of metallurgy, introducing widespread iron production. However, it is crucial to note that iron was not a novel discovery during this period. Artifacts made from iron, such as the renowned iron dagger found in the tomb of Egyptian king Tutankhamun, date back to the Bronze Age. Initially, the earliest iron objects were crafted from naturally occurring metallic iron sourced from meteorites, making them exceedingly rare and more valuable than gold. The advent of extractive iron metallurgy fundamentally transformed this landscape.
The ability to extract iron from ore and forge it into practical tools and weapons represents one of the most significant technological advancements in human history. Although the transition into the Iron Age was gradual, it eventually paved the way for the rise of powerful iron-wielding armies, such as those of Assyria and Rome, and later innovations like railroads and steel-frame buildings during the Industrial Revolution.
Dr. Nathaniel Erb-Satullo, a Visiting Fellow in Archaeological Science at Cranfield University, highlighted the significance of the Kvemo Bolnisi site. He stated, "Iron is the world's quintessential industrial metal, but the lack of written records, iron's propensity to rust, and limited research on iron production sites have made uncovering its origins challenging. This makes Kvemo Bolnisi an exciting site." The findings indicate that ancient metallurgists were aware of iron oxide as a distinct material and were experimenting with its properties during copper smelting.
This research not only sheds light on ancient iron usage but also exemplifies the synergy between modern geology and materials science in deciphering the practices of ancient materials scientists. By analyzing slag, a seemingly mundane waste product, researchers can gain insights into the innovative techniques employed by these ancient craftsmen.
The groundbreaking study, titled Iron in Copper Metallurgy at the Dawn of the Iron Age: Insights on Iron Invention from a Mining and Smelting Site in the Caucasus, has been published in the Journal of Archaeological Science. This research was made possible through the generous support of the British Institute of Ankara, the Gerda Henkel Foundation, and the American Research Institute of the South Caucasus.
