In a new study, researchers analyzed 48 tiny bronze figurines and three copper ingots to figure out where the metals came from and how artisans made them. The team used multiple isotope tests and chemistry to follow the trail from ore to object.

The results point to a metal network that linked Sardinia to Iberia around 1000 to 800 BC. They also clarify that Sardinia’s famous figurines were not simply made from one local recipe.

Importance of Sardinia’s figurines

The bronzes belong to the Nuragic culture of Sardinia, known for stone towers called nuraghi and for small bronze statuettes called bronzetti. These figures were often left at sanctuaries as offerings, and they depict warriors, leaders, animals, and boats.

Daniel Berger of the Curt-Engelhorn Center for Archaeometry in Mannheim (CEZA) led the lab work and data interpretation for the study, in collaboration with colleagues in Denmark, Italy, and Germany.

The bronzetti are ideal test cases because they were made on the island. If we can trace their metals, we can learn about Sardinia’s role in Bronze to Iron Age trade.

Fingerprinting ancient alloys

The team combined lead isotope analysis with copper, tin, and osmium isotopes. Each method adds a piece to the puzzle, since ore bodies carry distinct elemental and isotopic fingerprints that survive smelting and casting.

Lead isotopes help match objects to mining districts, but overlaps can blur the picture. Osmium isotopes are rarely used in archaeology, yet they proved especially helpful here because they captured signals that lead isotopes alone could not.

Sampling was careful and selective. Analysts avoided corroded regions when measuring trace elements to make sure the numbers reflect the original alloy rather than weathering.

Sardinian copper sources

The bronzetti from one major sanctuary form a clear pattern that indicates mixing of different copper sources before casting. This is not random recycling, but deliberate blending of distinct metal stocks.

One copper pool matches southwest Sardinia, in the Iglesiente-Sulcis district. Within that district, the Sa Duchessa mine is the strongest candidate based on the combined isotope and trace element signals.

A second copper pool points to Iberia, especially deposits in the Alcudia valley or Linares areas. Those signatures appear in several figurines from Sardinia and show that island workshops sometimes blended local copper with imported metal.

Two sources, one bronze

The osmium readings are striking. Samples tied to Sardinia show unusually radiogenic osmium values, consistent with local geology, which helped rule out copper from the Levant for these figurines.

The Iberian-like pool carries less radiogenic osmium and different lead ratios. That contrast makes the case for mixing two supply streams during the late Nuragic period.

This mixing was not constant across sites, hinting at workshop choices, market availability, or both. It also suggests that Sardinia’s role was active rather than peripheral.

Pinpointing the source of the tin

Bronze is copper plus tin, yet the tin in these figurines does not match known Sardinian ore. The tin isotope values point to imports, likely from elsewhere in Europe, which aligns with broader evidence that tin traveled long distances in this era.

Tin isotopes have become a key tool for this question. A prior study on Late Bronze Age tin ingots showed how tin and lead isotopes, together with trace elements, can narrow down sources across the Mediterranean.

Cassiterite, the main tin ore, varies by region. The figurines’ tin looks lighter than Sardinian cassiterite, strengthening the case for nonlocal supply.

Fingerprints in the copper

Lead isotopes alone can be ambiguous because different regions sometimes overlap. That is why the osmium signal mattered so much in this work.

“The results show that bronzetti was primarily made from copper from Sardinia, sometimes mixed with copper from the Iberian Peninsula,” said Berger. The team could also exclude Levantine copper for these objects based on osmium.

Using several isotope systems together reduces the risk of misattribution. It also helps separate natural impurities from later additions when artisans alloyed or refined the metal.

Sardinia as copper hub

For decades, scholars debated whether Sardinia mainly received metals from abroad or tapped its own copper. A 2023 study reviewed that debate and argued the island may have been more autonomous than once thought.

The new isotope data back that view by confirming active use of Sardinia’s copper alongside imported Iberian metal. It shows choice, not dependence.

This is a significant shift for how we model exchange, workshop organization, and political economy in the west-central Mediterranean.

Workshop metal selection

If sanctuaries curated both ingots and finished pieces, they likely sat inside a triangle that linked mines, villages, and ritual centers. The chemical evidence matches that kind of movement and storage.

Workshops probably selected copper based on availability, casting needs, or desired color and strength. Mixing two copper pools would have allowed smiths to fine-tune melt behavior without sacrificing durability

The absence of Cypriot copper in these figurines, despite many oxhide ingots on the island, suggests that specific object types followed distinct metal streams.

Small figurines, big routes

The bronzetti are small, but the science behind them expands the map of who traded with whom. Sardinia shows up as a producer that knew its own ore and navigated choices among foreign supplies.

Iberian ties add a western thread to networks often told as an east-to-west story. Tin’s nonlocal signature weaves in yet another route.

A figure that is only a few inches tall can carry the story of mines, voyages, and workshops across hundreds of miles. That is the power of careful measurements and cautious interpretation.

The study is published in the journal PLOS One.

Image Credit: Berger et al., 2025, PLOS One, CC-BY 4.0

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