TODAY, it looks like rusty, corroded junk, but 4000 years ago it was the very height of Bronze Age bling.

The ancient artifact – a prehistoric halberd made out of copper – was unearthed on the island of Bute and shows just how wealthy our ancestors were.

The rare weapon would have been priceless in its day, yet it was buried between 2500-2000BC, at the start of the Bronze Age, in an offering to the Gods. Scholars know little about the people who lived in Scotland in this period but the find shows that they had extreme levels of disposable wealth.

The halberd was found lying in a field near Kingarth on Bute by a local resident last year.

Research by experts at National Museums Scotland (NMS) has concluded the weapon was buried as a sacrifice to unknown deities worshipped by prehistoric people.

Five other halberds were discovered at the same site 150 years ago but are largely forgotten by modern scholars. The latest find has re-ignited interest in discovering what the artifacts teach us about Scotland's ancient past.

Trevor Cowie, a senior curator in the department of Scottish history and archaeology at NMS, said the museum has had three of the five halberds in its possession since the 1860s.

"Everything pointed to this [new find] being another one from exactly the same find spot," he said. "That really spurred me to do a bit more detective work on the three we had in our collection and the new one."

Cowie said the number of halberds deposited at the site was significant and indicated they had been placed there as some kind of votive offering.

"Because they were put into what was boggy ground, a wetland area, there was probably no intention to retrieve them," he said. "It doesn't really make sense to explain it as objects put there for safekeeping, so they have probably been placed there as some sort of sacrifice.

"There may well have been other things that went into the bog at the same time, like animal offerings or whatever, but in this case we just can't say."

The halberd blades – which would once have been attached to a wooden shaft – were previously believed to have been ceremonial items. But research indicates they were likely to have been used as weapons.

The artifact was uncovered by local resident Jessica Herriot, an archaeology enthusiast, who knew of the original halberd haul back in the 1860s. She visited the site while drainage work was taking place.

"I decided to go and have a look and see if anything had come to light," she said. "I literally walked through the gate and ... there it was lying at my feet.

"It was incredibly humbling to be the first person to hold it since it had been placed into the earth."

Paul Duffy, deputy project manager of archaeology for the Discover Bute Landscape Partnership Scheme, said the find had given more insight into the type of people living on the island in prehistoric times, who were likely to have lived in small farming communities.

"They have obviously got the money to be able to afford these halberds – which are quite 'Bronze Age bling' and quite high status – and then deposit them in the ground," he said.

"If you think of the fire and the smoke associated with making them and the fact you probably only had a few people that knew how to get the copper out of rock and create copper, then it is quite a magical process."