People have been warned not to clean their old coins because they could be worth a small fortune.
Coins
A TikTok user explained that due to the amount of coins made each day by the Royal Mint, "mistakes can happen" which can add value to the piece.
In a video, @CoinCollectingWizard told his followers: "You should never clean your coins and here is why...
"A 2p coin is usually in copper colour but instead this particular coin was accidentally minted on the same base as a 10p coin.
"The Royal Mint manufactures between [three to four] million coins a day, so it's understandable that sometimes mistakes can happen.
"The penny is known as a mule or an error coin making them 'super rare' which makes it 'super valuable' to collectors as they're nearly one-of-a-kind."
Such coins can actually be "nearly one-of-kind", while one 2p piece from 1983 could be worth over a grand.
He added: "But if you think that is special, check out the next coin.
"The 1983 New Pence Two Pence is considered rare due to a specific transition in the design.
"In 1983, the Royal Mint began the process of changing the inscription on the coin, from New Pence to Two Pence. If you find this rare coin, you are looking at £1,000+."