The pierced silver object is thought to be more than 1,600-years-old and was discovered in a field in Eaton Ford on May 5. Details of the find, described as a rare modification by a curator at the British Museum, were only made public last week. The coin, one of several items at the inquest at Lawrence Court, in Huntingdon, on May 18, where it was down to the deputy coroner of Cambridgeshire and Peterborough, David Morris, to determine if the find should be officially classified as treasure. After its discovery, the coin was sent by a local finds liaison officer to the British Museum in London, where it was examined and determined that because it had been modified it was treasure. The inquest heard that the coin was discovered by David Metson, in a field owned by David Evans, in Eaton Ford. In a report from the British Museum, Mr Morris said: Normally a single silver coin found on its own would not meet the criteria for treasure under the terms of the Treasure Act 1996. In this case, however, modification of the coin into a pendant has removed it from circulation and transformed it into an object. The coin depicts Roman emperor Gratian from the period of 367-383AD and on the reverse the legend read VRBS ROMA, wolf and twins, and the illustration shows Roma seated facing left holding victory on globe. Following its declaration as treasure, St Neots Museum has expressed interest in adding the coin to its collection.