Rare artefacts found in Sweden highlights the trade of metals of the Iron Age between the Atlantic and the Baltic Sea

In new research, archaeologists have examined a round object in heavy metal in Särdal in the West Swedish region of Halland. Due to its shape and size, it seemed to researchers an artifact of the Bronze Age, but the object has proven to be made of a copper-zinc-tin-lead alloy, typical of the Iron Age and Subsequent periods.

The old ingot was found in the fall of 2022 in the village of Särdal along the west coast of Sweden.

The artifact turned out to be a so-called Lingot Plano Convex-the first of its kind never found in the country.

“Plano-convex ingots, often also called” bun “or” casting cakes “ingots, are common throughout the Bronze and Iron Age, but vary in size, in shape and composition,” said Serena Sabatini and colleagues from the researcher at the University of Gothenburg.

“These are round artefacts with a generally flat upper side or a upper side and a varied convex back or underside.”

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

“Most of these ingots have an upper` `sparkling ” and rough, confirming that the metal was poured into an open molding mold, while the underside is generally smooth because it was not in contact with air during production.”

“Being a relatively simple product, they are widely distributed in Eurasia and have been used not only in prehistoric but also on historical times.”

The Särdal Lingot has a diameter of 14 to 5.3 cm, about 2.5 cm thick and weighs 1223.5 grams.

The surface of the ingot shows significant traces of corrosion, in particular on the more rough surface of its advantage.

The overall shape, the size and weight of the ingot strongly suggested that it could be a discovery of the Bronze Age.

“Initially, we thought that the Särdal ingot dates back to the Bronze Age,” said archaeologists.

“However, as it was noted alone and could not be dated by its archaeological context, we decided to disseminate isotopic and chemical analyzes to determine its composition and suggest a possible chronology.”

The analyzes provided unexpected results because the ingot has proven to be made of a copper-zinc-tin-lead alloy which was typical of the Iron Age and subsequent periods.

“Once the results have arrived, and thanks to the open character of the international scientific community of researchers working with archaeometallurgical problems in the past, we have realized that the isotopic and elementary characteristics of the Särdal Lingot were very close to a group of artifacts of two possible researchers found in the region of Iława Lakeland, in northeast of Poland,” said researchers.

Studies from the Baltic regions, which were intensely in network with Western Sweden and South Scandinavia during the pre-Roman Iron Age, indicate that the alloy of the type of Särdal and Iława Lakeland was present in the region already during the second half of the 1st millennium.

“We therefore propose that the Halland Plano-Convex Lingot and the Lingots of Polish stem can both be considered as the result of maritime metal trade connecting Scandinavia and the Baltic Sea to the Iberian Peninsula during the period corresponding to the Scandinavian Pré-Fer age, according to the old roads in progress since the bronze age”, concluded the authors.

Their article will appear in the October 2025 issue of the Journal of Archaeological Science: Reports.

_____

Serena Sabatini and al. 2025. Metallic trade of the Iron Age between the Atlantic and the Baltic Sea: new ideas of the first complete planned plank of Plano-Convex found in Sweden and Lingot stems of the Iława Lakeland in northeast Poland. Journal of Archaeological Science: Reports 66: 105312; DOI: 10.1016/J.Jasrep .2025.105312