2,900-Year-Old Steel Tools Discovered In Portugal Have Archaeologists In Awe

A multidisciplinary and international team led by Dr. Ralph Araque Gonzalez of the University of Freiburg’s Faculty of Humanities carried out the study. Ancient Iberian stelae, upright monuments often inscribed with information in the form of text, images, or a combination of the two, were determined to be formed of silicated quartz sandstone after the researchers conducted geochemical analysis on them.

The ramifications were audible right away.

“Just like quartzite, this is an extremely hard rock that cannot be worked with bronze or stone tools, but only with tempered steel,” says Araque Gonzalez.

Prior to the Romans: Steel

The researchers examined an iron chisel from the Final Bronze Age that was also discovered in Rocha do Vigio, Portugal, to validate their suspicion that these monuments were engraved with steel instruments. To work with the tough silicated quartz sandstone, they learned that the chisel was composed of heterogeneous but remarkably carbon-rich steel.

The researchers also tried working the rock that the stelae were constructed of using chisels made of various materials in an experiment with a professional stonemason, a blacksmith, and a bronze caster. The stone could only be engraved with the tempered steel chisel.

The discovery has significant ramifications for how quartzite sculptures and iron metallurgy are evaluated archaeologically in other parts of the world. Up until today, it was thought that neither the Early Iron Age nor the Final Bronze Age could have produced steel of a satisfactory quality.

Pieces of ironware unearthed from the Anatolian archaeological site of Kaman-Kalehöyük, dating from 1800 BC, are nearly 4,000 years old and represent the earliest known manufacturing of steel. However, it wasn’t until the majority of Bronze Age civilizations fell into disrepair around 500 BC—which opened the door for the vast empires of Rome and Han China—that iron and steel started to become a plentiful resource.

The Rocha do Vigio chisel’s discovery and the context in which it was discovered lead researchers to believe that iron metallurgy, including the production and tempering of steel, was likely an indigenous development of decentralized small communities in Iberia rather than the result of later colonization processes. Why steelmaking did not spread from this part of Iberia to other continents is unknown.

In many areas of the Iberian Peninsula, the Late Bronze Age archaeological record is patchy, with few settlement remnants and almost no discernible burials. However, the western Iberian stelae, with their depictions of anthropomorphic figures, animals, and particular objects, are of particular significance for the study of this period.

The finding of steel tool use during this time reveals new information on the technological development of ancient communities and their capacity to work with difficult materials.