A "rare" 650-year-old coin has been found in a secret drawer in a desk left to a woman by a long-lost relative.
The 14th Century coin was discovered inside one of three hidden drawers in a 20th Century bureau.
Amy Clapp, from Derbyshire, inherited the piece of furniture from a great cousin and had taken it to be valued.
Don Collins, of Hansons Auctioneers, said the 22-carat coin was "very unusual" and he had "never seen one exactly like it" in more than 50 years.
Experts believe the Raymond IV Prince of Orange Franc A Pied, dating back to 1365, could fetch double the guide price of £1,200 to £1,800 when it is auctioned in March.
Mrs Clapp, 37, said she did not remember meeting her distant relative and had "no idea" the coin or the secret drawers existed when she took the George II-style bureau for a valuation.
Edward Rycroft, from the auction house in Etwall, Derbyshire, 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."
Mr Rycroft said he knew straight away the coin was "really special".
"It's the most amazing thing I have ever found by chance," he added.
Mrs Clapp said she "would never have found that in a million years" and hoped to donate some of the sale proceeds to a charity.
The wooden bureau is due to go under the hammer on Wednesday estimated at about £80, while the coin will be auctioned separately next month.