The rectangular brooch, dating from AD 1230 to 1350, will now be valued by a panel at the British Museum along with other treasures from around the UK.
Oxfordshire County Council’s museum service will then apply for grants so it can buy back local discoveries and put them on public display.
The gold brooch was dug up by Chinnor metal detectorist Kevin Ford in a field not far from his home in the village on Wednesday, August 26.
Finds Liaison Officer for Oxfordshire Anni Byard said today it stood out because it was in “very fine condition”.
She added: “This brooch is unusual because of its quality and completeness: you could almost wear it now, and considering it’s about 800 years old, that is very nice”.