A gold coin, estimated to be worth up to £3,000, has been found inside a hidden drawer of a wooden bureau valued at just £60.
The Raymond IV Prince of Orange Franc A Pied coin dates back to 1365, making it more than 650 years old.
Its guide price is £1,200 to £1,800, but experts think it could sell for as much as £3,000.
Amy Clapp, 37, from Derbyshire, was given the 20th century George II-style bureau by a long-lost distant cousin. It is estimated to be worth £60 to £80.
Mrs Clapp said: “I can’t even remember meeting my great cousin but I received a letter from a solicitor before Christmas informing me that I’d been left various items of furniture. Apparently, the will was written when I was 13 years old.”
Mrs Clapp had no idea the hidden drawer, which had kept the 14th century French gold coin hidden, even existed until she took it to an auctioneers.
The coin was discovered by furniture valuer Edward Rycroft, at Hansons Auctioneers, London.
During an inspection he found three secret drawers within the bureau, one containing the 22ct gold coin.
Mr Rycroft said: “I know bureaus like this often have tiny, secret drawers – sometimes called coin drawers – so I always check them just in case.
“But in 10 years of valuing furniture I have never found anything in them – until now.”
Mrs Clapp, a family support worker, said she was delighted when Mr Rycroft rang to tell her the news: “As a family, we’ve had some bad luck in the last two years, so for something like this to happen to us is amazing.
“My daughter, Abi, 18, was recently registered as severely impaired. She has Bardet-Biedl syndrome, a genetic condition which affects vision as well as other parts of the body. I work for the Bardet-Biedl Syndrome UK charity and I’ll be donating some proceeds from the sale to it.
“I would never have found that in a million years. We’re so grateful to Edward. We recently blew all our savings on a car and its engine blew up shortly after we bought it, so any windfall is very welcome.”
Mr Rycroft said he knew straight away the coin was “really special”.
“It’s the most amazing thing I have ever found by chance. If you’ve got an old bureau at home do check for secret drawers – you never know, you may be sitting on a windfall too,” he added.