About £40,000 is needed to keep an important collection of Anglo-Saxon jewellery in Norfolk.
The brooch has an inscription on the back
The Harford Farm hoard was found in a Saxon cemetery unearthed by archaeologists between 1989 and 1990 before Norwich's southern bypass was built.
The grave-goods were loaned to the county's museum service by the landowner - but he has now died, and the executors of his will must sell the treasures.
Tim Pestell of the Norfolk Museums Service said the 7th Century collection was "exactly the sort of thing we want to see because it tells a fantastic story.
"This is the moment in time that the Anglo-Saxon people in East Anglia gave up their pagan beliefs and became Christians, and we can see that in their objects.
"They're burying their objects with the dead, but at the same time they're beginning to use coins, adopt Christianity and become subjects to kings and other aristocratic rulers."
The excavations took place in 1989 to 1990
The most important of the treasures is a gold brooch with a runic inscription reading "Luda repaired this brooch".
Other items include gold and silver pendants and a silver animal head with glass eyes.
The haul has been valued at almost £92,000.
So far, the Friends of Norwich Museums have raised £10,000 and the National Art Collections Fund has pledged almost £42,000.
If the appeal is successful, the collection will form the centrepiece of a new Anglo-Saxon and Viking Gallery at Norwich Castle.
If not, it could be sold on the open market.