The ancient ingot was discovered in the fall of 2022 at the town of Särdal along the west coast of Sweden.

The artifact showed to be a so-called plano-convex ingot– the very first of its kind ever discovered in the nation.

“The plano-convex ingots, frequently likewise called ‘bun’ingots or’casting cakes,’prevail throughout the Bronze and Iron Age, however differ in size, shape, and structure,” stated University of Gothenburg scientist Serena Sabatini and coworkers.

“They are round artifacts with an usually flat upper face or topside and an otherwise bulged convex bottom or underside.”

“They are made by putting the melted metal into a mould or in a shallow cavity in the ground.”

“Most of those ingots have a ‘bubbly’ and rough upper face, validating that the metal was gathered an open casting mould, while the underside is normally smooth as it was not in contact with air throughout production.”

“Being a reasonably easy item, they are commonly spread out throughout Eurasia and have actually been utilized not just in ancient however likewise in historic times.”

The Särdal ingot is 14-15.3 cm in size, around 2.5 cm thick, and weighs 1223.5 grams.

The surface area of the ingot reveals considerable traces of deterioration particularly on the rougher surface area of its advantage.

The total shape, size, and weight of the ingot highly recommended that it might be a Bronze Age discover.

“Initially, our companied believe the Särdal ingot to go back to the Bronze Age,” the archaeologists stated.

“However, as it was discovered alone and might not be dated by its historical context, we chose to run isotopic and chemical analyses to identify its structure and recommend a possible chronology.”

The analyses supplied unanticipated outcomes as the ingot ended up being made from a copper-zinc-tin-lead alloy that was common of the Iron Age and later on durations.

“Once the outcomes showed up, and thanks to the open character of the global clinical neighborhood of scholars dealing with archaeometallurgical problems in the past, we understood that the isotopic and essential attributes of the Särdal ingot were really near a group of artifacts from 2 possible stockpiles discovered in the Iława Lakeland area, in northeastern Poland,” the scientists stated.

Research studies from the Baltic areas, which were extremely connecting with West Sweden and southern Scandinavia throughout the pre-Roman Iron Age, show that the alloy of the type from Särdal and the Iława Lakeland existed in the location currently throughout the 2nd half of the 1st millennium BCE.

“We propose for that reason that the plano-convex ingot from Halland and the rod ingots from Poland can be both thought about the result of maritime sell metal linking Scandinavia and the Baltic Sea to the Iberian Peninsula throughout the duration representing the Scandinavian pre-Roman Iron Age, following ancient paths in usage given that the Late Bronze Age,” the authors concluded.

Their paper will appear in the October 2025 problem of the Journal of Archaeological Science: Reports

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Serena Sabatini et al2025. Iron age metal trade in between the Atlantic and the Baltic Sea: brand-new insights from the very first total plano-convex ingot discovered in Sweden and ingot rods from the Iława Lakeland in northeastern Poland. Journal of Archaeological Science: Reports 66: 105312; doi: 10.1016/ j.jasrep.2025.105312