In 2009 to celebrate the 40th Anniversary of the first UK 50p Fifty Pence Coin, the Royal Mint released a very special Limited Issue Kew Gardens Piedfort 50p Fifty Pence Gold Proof Coin struck in solid 22 Carat Gold Certified Slabbed and Graded by NGC as PF69 Ultra Cameo and was only available from the 40th Anniversary of the 50p Piedfort 50p Gold Proof 16 Coin Set.
The coin weighs 31.10 grams and is double the thickness of its normal counter-part and has a strict mintage of only 40 worldwide and is the smallest issue ever of any United Kingdom coin.
The reverse, designed by Christopher Le Burns has chosen to feature Kew famous Chinese Pagoda while the obverse has the stunning portrait of Her Majesty Queen Elizabeth II by Ian Rank Broadley.
These legal tender coins have been struck to proof quality using specially prepared dies and highly polished blanks.
Piedforts are coins which have been specially struck on thicker than normal blanks.
As their name suggests they are closely associated with France, where from the twelfth century they were apparently issued by the Kings as presentation pieces.
In Britain the practise of striking Piedforts is later and less frequent, but medieval and Tudor examples are known