It was a sorry-looking object when it was unearthed in 2014 from a ploughed field in western Scotland, having been buried for almost a thousand years ago.

Now an extraordinary treasure has emerged – a spectacular Roman rock crystal jar wrapped in the most delicate gold thread by the finest medieval craftsman in the late 8th or early 9th century.

It was part of the Galloway Hoard, the richest collection of rare and unique Viking-age objects ever found in Britain or Ireland, acquired by the National Museums Scotland (NMS) in 2017.

Buried around AD900, it contained around 100 artefacts from the Anglo-Saxon kingdoms, Ireland and as far away as Asia.

It was unearthed by Derek McLennan, a retired businessman, who was out with his metal detector on church-owned land in Kirkcudbrightshire, southwestern Scotland.

This Roman rock crystal jar was wrapped in delicate gold thread by some of the finest medieval craftsman in the late 8th or early 9th century

The small jar was found as part of the Galloway Hoard in 2014 and acquired three years later by the National Museums Scotland

The crystal jar’s base is decorated with swirling gold ornaments in a lavish display of wealth. The hoard was found by Derek McLennan, a retired businessman, who was out with his metal detector on church-owned land in Kirkcudbrightshire, southwestern Scotland

Experts were initially unaware of the jar’s value as it was shrouded in a shrivelled pouch that was masking its true value

Once the cleaning process started it became clear it was far more valuable than originally thought. Pictured:The jar before the final stage of restoration

The protective pouch had become so hardened that the object paled against other treasures that included a gold bird-shaped pin and a silver-gilt vessel.

That the pouch was originally silk-lined leather reflects the significance of its contents.

The jar, which is about 5cm tall, is thought to have contained a perfume or other precious potion that could have anointed kings or been used in religious ceremonies.

Dr Martin Goldberg, the NMS’s principal curator of Early Medieval and Viking collections, discovered that it was all the more exceptional because the rock crystal carving was in fact Roman and perhaps 600 years old by the time it was converted into a gold-wrapped jar.

He hopes that its potion can be revealed from trace elements that might have survived. The rock crystal was carved with lobes that resemble foliage. The jar had been drilled through, aligning with a spout at the top.

Dr Leslie Webster, former keeper of Britain, Prehistory and Europe at the British Museum, said: ‘Rock crystal is unusual in itself.

‘It is one of those materials that was greatly prized in the antique world, for its transparency and translucency, and so it’s ᴀssociated with purity. So it was, I think even in its time, very, very special.

‘And you can see from the way that the gold almost enshrines it, it’s made into a sort of relic.

‘It’s a showcasing piece from a very high-status workshop, such as one that you might expect a bishop to have in one of his monasteries. This object is absolutely fascinating.’

Experts were astonished to find a Latin inscription that said ‘Bishop Hyguald had me made,’ in gold letters on the jar’s base.

It was a sign some of the hoard’s material may have come from a church in the Anglo-Saxon kingdom of Northumbria, which included Dumfries and Galloway and extended as far north as Edinburgh and as far south as Sheffield.

At the beginning of the 10th century, Alfred the Great was defeating the Danes and laying the foundations of medieval England and Alba, the kingdom that became medieval Scotland.

This was a time when ecclesiastical treasures were being robbed from monasteries and the hoard could have been buried by a Viking or someone fearing a further raid.

Even the silk was then a particularly precious material, imported thousands of miles from Asia.

Church chronicles of the period are incomplete but Dr Goldberg spoke of the excitement at finding a named individual.

He said: ‘So much of the past is anonymous, especially when you’re looking at very early history.’

Ninety-seven of the hoard’s artefacts are included in a touring exhibition, тιтled Galloway Hoard: Viking-age Treasure.

The exhibition is at Kirkcudbright Galleries until July 10, transferring to Aberdeen Art Gallery from July 30 to October 23.

The jar is still undergoing final work, but, from Monday, December 20, a new film and digital model will be on show.