Green, kidney-shaped and weighing nearly a tonne, it is no thing of beauty. Yet the Grouville Hoard is a treasure trove and time capsule in one - and today it starts giving up its secrets.

The world's largest hoard of Celtic coins was found in 2012 buried in a field in the Channel Island of Jersey. The hunk, which is 1.8m (6ft) long and 20cm deep, contains more than 70,000 coins glued together by verdigris and the clay they were buried in more than 2,000 years ago. Starting today, the solid mass will be dismantled, coin by coin, before each is identified, cleaned and catalogued.

The hoard was uncovered by Reg Mead and Richard Miles, two treasure hunters who had been searching the same field for more than 30 years after hearing of the discovery in the 1950s of another, far smaller hoard. They have joined conservators and Celtic coin experts in a laboratory in Jersey Museum, where members of the public are able to watch the delicate operation.

Thought to be worth as much as £10 million, the hoard, also known as Le Catillon II, was buried some time after Julius Caesar's conquest of Gaul in 52BC. It would have consisted of a large part of the portable wealth of the Coriosolitae tribe who lived in Armorica, the area of modern-day Brittany around St Malo and Dinard.

The task of prising apart, cleaning and cataloguing the coins is expected to take at least three years. The plan is to remove between 60 and 70 a day, but no one knows exactly what lies within, as the lump is too thick to be x-rayed. Among the coins are tantalising glimpses of gold jewellery, hinting at more hidden treasures to come.

As Caesar wrote the only historic record of events in Gaul at that time, it may never be known what tribal conflicts prompted the flight to Jersey and the burial of the hoard.

What is clear is that people were hiding money on the island long before it became an offshore tax haven. Nearly a dozen smaller hoards from about the same period, totalling more than 100,000 coins, have been discovered.

David adds:

To read the complete article, see:Celtic hoard begins to give up its secrets after 2,000 years(www.thetimes.co.uk/tto/news/uk/article4181529.ece?shareToken=6645635c736a808fb22df2d42fb36e4a)

Work to separate 70,000 Celtic coins and pieces of jewellery is taking place under the public gaze at Jersey Museum.

Researchers aim to remove and clean up to 500 coins a week for the next three years in a specially built glass-walled lab.

For the past two years the team, led by Jersey Heritage conservator Neil Mahrer, has been documenting the hoard, which is about 2,000 years old.

Mr Mahrer has been using a £40,000 laser scanner to create detailed three-dimensional imagery of the find.

The laser is so precise it can pick out intricate patterns minted thousands of years ago.

Once scanned, the coins will be separated, dipped in formic acid, washed and meticulously cleaned by hand under a microscope.

"It's very important to us to have the best possible record of the hoard the way it was found before we start taking it apart, because we only get one shot at it," said Mr Mahrer.

"We still can't see inside the thing. We tried to find out about getting it x-rayed but it's just too big and too thick so all we can do is look at the surface.

"What will come out over the next three years will be a surprise to us all."

To read the complete article, see:Jersey hoard: Archaeologists unpick 70,000 coins(www.bbc.com/news/world-europe-jersey-28900555)