The Royal Mint is encouraging people to rummage through their loose change to discover whether they have a rare 50 pence piece.
Around one in 300 people is estimated by the Mint to have the Kew Gardens coin in their possession after it was released into circulation in 2009 to mark the 250th anniversary of the Royal Botanic Gardens.
The Mint described the coins as "incredibly rare", so much so that it is the rarest commemorative coin design to be placed into general UK circulation, with just 210,000 of them ever released.
The Kew Gardens coin, which features a design showing the pagoda of the Gardens encircled by a twisting vine plant, is already prized by collectors and a search on the eBay auction website showed that several have recently sold for upwards of £20.
Designed by Christopher Le Brun, the coin bears the dates 1759 and 2009 and says "Kew" at the base of the pagoda.Shane Bissett, director of commemorative coin at the Royal Mint,
Designed by Christopher Le Brun, the coin bears the dates 1759 and 2009 and says "Kew" at the base of the pagoda.
The Mint is inviting people to share a photo of their Kew Gardens 50 pence on the Mint's Facebook page or on Twitter at #strikingstories.
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