The researchers used an advanced technique called laser ablation mass spectrometry to sample gold from 50 early Bronze Age artefacts.

Archaeologists have found evidence of an ancient gold trade route, dating to the early Bronze Age (2500 BC), between the southwest of Britain and Ireland.

Using a new technique to measure the chemical composition of some of the earliest gold artefacts in Ireland, the researchers determined that the objects were actually made from gold imported from Cornwall in Britain.

“This is an unexpected and particularly interesting result as it suggests that Bronze Age gold workers in Ireland were making artefacts out of material sourced from outside of the country, despite the existence of a number of easily-accessible and rich gold deposits found locally,” said lead author Chris Standish from University of Southampton in Britain.

“It is unlikely that knowledge of how to extract gold did not exist in Ireland, as we see large scale exploitation of other metals. It is more probable that an ‘exotic’ origin was cherished as a key property of gold and was an important reason behind why it was imported for production,” Standish said.

The researchers used an advanced technique called laser ablation mass spectrometry to sample gold from 50 early Bronze Age artefacts in the collections of the National Museum of Ireland, such as; basket ornaments, discs and lunula (necklaces).

They measured isotopes of lead in tiny fragments and made a comparison with the composition of gold deposits found in a variety of locations.

After further analysis, the archaeologists concluded that the gold in the objects most likely originates from Cornwall, rather than Ireland — possibly extracted and traded as part of the tin mining industry.

The study appeared in the journal Proceedings of the Prehistoric Society.