Scientists have used a new ‘archeometallurgical’ approach to determine the origins of metals used by the Bronze Age Nuragic culture to make Sardinia’s iconic ‘bronzetti’ figurines.

Bronze is an alloy made mostly of copper, with about 12% of tin and other metals such as lead. The findings suggest that while the Nuragic exploited local sources of copper, they did not use Sardinia’s tin and lead in the construction of bronzetti during the early first millennium BCE.

“The results show that bronzetti was primarily made from copper from Sardinia, sometimes mixed with copper from the Iberian Peninsula (modern-day Spain and Portugal),” says Daniel Berger from the Curt-Engelhorn Center for Archaeometry, Germany, first author of a paper reporting the findings in PLOS One.

“The study also revealed that copper from the Levant – places like Timna in Israel and Faynan in Jordan – was not used in Sardinia, which was only made clear by looking at osmium isotopes.”

The warrior bronzetti from Abini, central Sardinia. Most bronzetti are shown with a weapon set consisting of different combinations. This bronzetti is part of the archer group and features a sword, bow, arrows, and elements of body armour, including the typical horned helmet. These horned helmets are worn by warrior statuettes. Credit: picture are taken by Heide W. Nørgaard with permission of the Museo Archaeologica Nazionale di Caglairi.

The Nuragic flourished on the island now known as Sardinia in Italy during the archaeological period known as the Bronze Age. The culture is known for its construction of stone towers, called Nuraghe, of which more than 7,000 still stand across the island today.

They are also known for the bronzetti figurines, which according to the authors of the study “represent diverse facets of Nuragic society, including the so-called ‘chieftains’, warriors, offerers, animals, and boats”.

“Scholars have identified 2 groups of bronzetti: the earlier and more prominent Uta-Abini figurines (c. 950–800 BCE) and the later, rather marginal Mediterraneizzante figurines (c. 800–700 BCE),” they write.

The researchers analysed fragments from 48 bronzetti dating to late Nuragic which were recovered from 4 sites. They used a new approach which integrates conventional trace-element and lead isotope analyses with rarely used copper, tin and osmium isotope measurements.

A bronzetti picturing another kind of warrior found in the sanctuary of Santa Vittoria di Serri in central Sardinia. This warrior type is only shown with a dagger and has a long, wide cloak. The hands of this bronzetti are broken; however, based on similar bronzetti, it might have shown the open hand gesture. Credit: picture by Heide W. Nørgaard with permission of the Museo Archaeologica Nazionale di Caglairi.

Isotopes of an element contain the same number of protons in the atoms’ nucleus but differ in the number of neutrons. The isotopic composition of a metal provides important information about where it originated from.

“The very latest geochemical knowledge points to the origin of the metal in specific geographical areas and certain mines,” says co-author Helle Vandkilde, a professor at Aarhus University in Denmark.

“It is also possible in several cases to trace a strategic mix of copper with different origins; Presumably to achieve certain effects such as the product’s colour and strength.”

The analysis indicates the copper came from the Iglesiente-Sulcis district in southwest Sardinia, most likely from the Sa Duchessa mine, and from the Alcudia valley or the Linares district in the Iberian Peninsula.

Another possible explanation for this mixing, according to the authors, “is that both foreign and local copper were reaching local markets and that Nuragic metallurgists simply picked what was immediately available or what was cheaper at the moment of purchase, without having particular preferences”.

Close up of a Nuragic bronzetti, a bronze statuette of circa 10cm height with the typical horned helmet and the welcoming hand symbol. The bronzetti was found at the Bronze Age sanctuary of Abini in central Sardinia. Credit: by Heide W. Nørgaard with permission of the Museo Archaeologica Nazionale di Caglairi

“This, for example, would explain why different batches of bronzetti from different sites have different compositions,” they add. “It is likewise possible that local copper deposits might have become exhausted in this late Nuragic period, necessitating the search for non-local alternatives.”

The tin isotope values of all the bronzetti also indicate that local Sardinian tin was not used in the figurines and must have instead been imported.

“Isotopically similar ores to the tin in the bronzes are widespread in other European deposits, especially in the large tin provinces of the Iberian Peninsula, of Cornwall/Devon, and of the Saxon-Bohemian Erzgebirge, but also in smaller deposits in the French Massif Central and farther away in Egypt,” the authors write.

“Since the transregional overlap in the tin isotope compositions is very large, the question of origin cannot be answered unequivocally.

“These results shed light on local metallurgical practices and distribution strategies in Nuragic Sardinia, but also on Sardinia’s broader role and position in the Mediterranean world during the transition from the Late Bronze Age to the Early Iron Age.”