More than 50 different designs, to commemorate special occasions, anniversaries or moments in history, have been released into circulation since 1969. Image: The Royal Mint.Ī 50 pence piece is Britain's most collectable coin, says the Royal Mint, and provides 'the ideal canvas' for a commemorative design. Scroll down for the full list The 50p coin celebrating 100 years of the BBC features the Queen's effigy on the other side having been made before she died. The Royal Mint's list of of 10 coins, that are the most unusual 50p pieces you could still find in purses, piggy banks or down the side of your sofa, could all potentially be valued at more than their 50p denomination, with mintage figures – the number of copies issued of each particular coin – serving as a helpful guide to the rarest coins. While the Royal Mint expects this extra-special coin – costing £11 – to be a big hit with those keen for their own little piece of unique Royal memorabilia, there are a number of 50 pence pieces still in circulation that collectors are also often keen to add to collections.