A Norwegian metal detectorist thought he had come across some chocolate money buried in the soil – but it turned out to be nine pendants, three rings and 10 gold pearls in what has been described as the country’s gold find of the century.

The rare discovery was made on the southern island of Rennesoey, near the city of Stavanger, by Erlend Bore.

The 51-year-old bought his first metal detector earlier this year as a hobby after his doctor ordered him to get out instead of sitting on the sofa.

Ole Madsen, director at the Archaeological Museum at the University of Stavanger, said that to find “so much gold at the same time is extremely unusual”.

“This is the gold find of the century in Norway,” he said.

In August, Mr Bore began walking around the mountainous island with his metal detector.

A statement issued by the university said he first found some scrap, but later uncovered something that was “completely unreal” – the treasure weighing a little more than 100 grams (3.5oz).

Under Norwegian law, objects from before 1537, and coins older than 1650, are considered state property and must be handed in.

Associate professor Hakon Reiersen, from the museum, said the gold pendants – flat, thin, single-sided gold medals called bracteates – date from around AD500, the so-called Migration Period in Norway, which runs between 400 and about 550, when there were widespread migrations in Europe.

The pendants and gold pearls were part of “a very showy necklace” that was made by skilled jewellers and worn by society’s most powerful, said Professor Reiersen.

He added that “in Norway, no similar discovery has been made since the 19th century, and it is also a very unusual discovery in a Scandinavian context”.

An expert on such pendants, Professor Sigmund Oehrl, also from the museum, said about 1,000 golden bracteates have so far been found in Norway, Sweden and Denmark.

He said symbols on the pendants usually show the Norse god Odin healing his son’s sick horse.

On the Rennesoey ones, the horse’s tongue hangs out on the gold pendants, and “its slumped posture and twisted legs show that it is injured”, Professor Oehrl said.

“The horse symbol represented illness and distress, but at the same time hope for healing and new life,” he added.

The Archaeological Museum in Stavanger, about 200 miles (300km) south-west of Oslo, plans to exhibit Mr Bore’s finds.