This gold and silver Iron Age torc (200-50BC) is valued at £350,000
There has been a significant rise in the number of valuable artefacts found by amateur treasure hunters in Britain.
The British Museum says the number of finds containing gold and silver rose by 12.6% to 749 in the last 12 months.
The most valuable discovery was a rare Iron Age necklace found near Newark in Nottinghamshire and worth £350,000.
Experts say the rise is due to the growing popularity of metal detectors and the legal obligation on treasure hunters to report their finds.
Any finds of gold and silver more than 300 years old are legally treasure trove and must be declared and valued by the government's Treasure Valuation Committee.
All such treasures ultimately belong to the Crown.
The new figures were revealed in the British Museum's annual report of treasure.
It said the total number of finds was 1,257, which included objects from 2005 and 2006 that have now passed through the treasure process.
In 2001, the report documented just 200 treasures.
The prize find, the gold and silver Iron Age necklace or torc, is believed to be about 2,000 years old.
It was unearthed by a man who was looking for parts of crashed World War II aircraft and is the most valuable single item to be discovered by a member of the public for more than a decade.
Recent finds included a haul of more than 3,500 Roman coins
Its discovery has forced historians and archaeologists to re-think the importance of the Trent Valley area.
Culture minister Barbara Follett said: "The treasures of the past that are found in the fields, farms and fells across the United Kingdom are vital pieces in the jigsaw puzzle of our history."
She also singled out former Rolling Stones bassist Bill Wyman as an "obsessive treasure finder".
Mr Wyman has a section dedicated to archaeology on his website.
The oldest object found in the last year was a long, cigar-shaped piece of gold found by a man detecting near Winchester, Hampshire.
It is believed to be Bronze Age, potentially dating from as far back as 1500BC.
Among the other discoveries were a gold and garnet Anglo-Saxon "mount" artefact and a collection of more than 3,500 Roman coins.
The Treasure Act in 1996 ruled that finders and landowners would be eligible for rewards for finds.
Museums have since reported a 10-fold increase in items of treasure offered to them.