George III sixpence brockage
Alongside the outstanding British coinage proof and pattern pieces in the Royal Mint Museum we also retain an extensive selection of mis-strikes and counterfeits. Despite being considered much less glamorous they are nonetheless interesting pieces. There are off-centre strikes and a whole host of other items including the coin illustrated, which is a sixpence brockage from the last coinage of George III.
For those unfamiliar with this type of piece it is always either double-headed or double-tailed, produced when a coin becomes locked onto one of the dies in a coining press and then acts as a kind of die itself. The result is that the next coin will be struck between a die and the trapped coin, giving it the same design on both sides, once as a normal relief impression and on the other side as an incuse impression. Such pieces, although obviously faulty, are of real interest because of what they can tell us about how coins are made; as well known American numismatist Harry Manville once said, "It is possible to learn more about the minting process from a mis-struck coin than from a perfectly struck coin".