Two years after the Staffordshire Hoard was discovered, the painstaking work of cleaning, and uncovering its origins is still ongoing. Neil Elkes reports.

There is a thrill in being the first person to see something which has been buried and caked in centuries-old soil for more than 1,300 years.

And it is that flutter of excitement that keeps the five-strong team of conservationists returning day after day to their lab at Birmingham Museum and Art Gallery, to meticulously clean tiny fragments of gold, part of the largest-ever haul of Anglo-Saxon artefacts ever discovered.

The painstaking cleaning process of pieces not much larger than a thumbnail can take up to 10 hours of gentle scrubbing, probing and washing, all under the glare of a microscope, to peel back layers of dirt and leave a sword pommel, or helmet decoration gleaming.

Then there are the eureka moments, those flashes of inspiration in which the pieces of this historical conundrum are literally pieced together like a jigsaw puzzle to reveal something new.

Just such a moment occurred for conservator Deborah Magnoler when she spotted something familiar about a gold cylinder, decorated with garnet stones, that she happened to be cleaning.

It occurred to her that the four tiny rivet holes and a central protruding block that had been uncovered beneath a layer of soil were similar to fixtures on the millifiori stud she had cleaned several weeks earlier.

The stud, a beautiful piece of 7th century craftmanship with a black and white check pattern, is one of the star items from the Staffordshire Hoard, discovered in a farmers field near Lichfield in 2009.

Returning to the safe, Deborah took out the pretty stud, carefully unwrapped it from the cotton wool and sure enough the holes matched.

She said: “It is a perfect fit. We had little idea what it might be for, other than to decorate something, and still we haven’t a clue.”

It is painstaking work, but for the team of three full-time conservators and their colleagues, seconded from various university archeology and conservation courses, it is those magical moments of discovery that make it worthwhile.

While their role is to clean and catalogue, much of the theorising and debate about their uses will follow. The results of the work are forwarded to expert archeologists and historians in universities around the world for analysis.

It is a similar process to those seen in forensic science labs on TV detective dramas – the boys and girls in the lab find the evidence, study the items, run the tests then leave it to the detective to come in with the winning theory.

Each of the team members is hunched over a microscope examining and cleaning a fragment, a piece of historic evidence, searching for clues to an item’s use, or some meaning in the imagery. The dirt is worked away and the detailed design can be seen by visitors on their monitor screens.

Being a soft metal, some with fixed garnet stones, only the gentlest treatment can be used to remove away the soil. It is here that all the high-technology equipment has to give way to Mother Nature.

Manager of the Hoard conservation project, Deborah Cane, explains: “We are working with hawthorn needles, or blackthorn or polyanthus, held in a pin vice to remove the soil.”

She explains that the thorns are fine enough to penetrate small crevices and work away the soil, while being soft enough to not tarnish or scratch the piece. Gardeners among the museum staff have been happy to donate their clippings for this delicate task.

Other than that, a little water or methylated spirits is used for the more stubborn caked-on soil.

“We have to be very careful, it is a slow, painstaking process. It takes an average of seven to 10 hours to clean each piece. It is very exciting, you are the first person to have seen that for more than a thousand years. It is a privilege,” Deborah adds.

Some very advanced technology is being used to further study the Hoard. Recently some gold was sent to the University of Southampton where it was put through a lengthy CT scan, revealing the internal structure of a five millimetre slice.

They have found some interesting structures inside a garnet stone which may give a clue to its origin, and perhaps explain trade routes to Anglo-Saxon England.

Earlier this year a special 3D microscope was borrowed to scan and capture some detailed computer images which can now be sent to universities around the world for detailed remote study.

The conservation team was set up after Birmingham Museum and Art Gallery and Stoke-on-Trent Potteries Museum raised the £3.2 million to buy the hoard. After several months only a fraction of it has been examined and cleaned. There is currently funding for two years’ further work and efforts are being made to raise more research and conservation money.

Some travelling exhibitions, including one to America currently under negotiation, could be a source of income for the project.

Many of the items, which are of a military nature, have been decorated with snakes, seahorses and even dragon images. But recently the team wiped the dirt away from a silver sword pommel to reveal a human face. The first, and so far only, depiction of a person on the treasure. The face is flanked by wings, while on the rear are two boars.

Again, this was uncovered by the team, but the debate about its significance and meaning will go on world-wide for some time.

Working with archeologists from the British Museum they have selected the pieces in order of historical interest, while others have been chosen for the Mercian Trail summer tour of Stafford, Lichfield and Tamworth. These are being cleaned first.

A key item, which has been highlighted since the discovery was first revealed to the world, was the crushed gold cross, which led some to speculate that the Hoard might have been buried by pagans, perhaps as the booty from a defeated Christian army.

That cross, and a replica, which shows how impressive it would have appeared unfolded and complete with garnet stone decoration, will be going on the Mercian Trail tour.

* Staffordshire Hoard: The Facts

* The Staffordshire Hoard dates from the 7th Century AD. It is the largest haul of Anglo-Saxon treasure ever discovered

* The collection of mostly martial items – sword fittings, armour with some religious items – were collected and buried in a hilltop what was the kingdom of Mercia

* Little is known about where it comes from, whether a single battle, or collected over a campaign, nor why the swords were singled out

* Key items include the folded cross, the millifiori stud, the pectoral cross, a strip of gold bearing a biblical inscription, a fragment from a helmet and a seahorse

* The craftsmanship on many items is exquisite andf finely detailed, some inlaid with garnet stones. It is likely it was owned by aristocracy

* It was discovered by Terry Herbert in summer 2009 while out treasure hunting with his metal detector. It was buried in a field near Burntwood, Staffordshire, owned by farmer Fred Johnson.

* An archeological dig uncovered the full extent of the find and the priceless items were taken to Birmingham Museum and Art Gallery for study and security

* A 19-day exhibition after the discovery was revealed attracted 65,000 visitors

* The purchase price of the Hoard was set at £3.2 million and the money was successfully raised to buy the Hoard for Birmingham Museum and Art Gallery and Stoke-on-Trent Museum. A large donation from the Art Fund and many individual donations helped the museums reach the target.

* While permanent exhibitions are established in Birmingham and Stoke-on-Trent, there are so many items that tours are being arranged. This summer exhibits are being held in the heart of the ancient kingdom of Mercia in Shire Hall, Stafford, from July 2–24, Lichfield Cathedral, July 30 to August 21 and Tamworth Castle from August 27 to September 18.