Like many other mints, the Royal Mint issues bullion coins in precious metals, having much higher intrinsic value than their face value. The half ounce (1/2 oz) gold coins are denominated as Fifty Pounds (£50).
The coins are legal tender but are not intended for circulation. They are targeted at bullion investors or collectors who appreciate the special editions as pieces of art. The mint makes a distinction between plain "bullion" coins (issued in Brilliant Uncirculated grade) and proofs; the "bullion-grade" coins have textured backgrounds of both the obverse and the reverse designs and use the generic "authoritative" design, while proofs are typically "one-year" types. They are usually issued in parallel with other denominations/sizes having the same reverse designs.
Celebrating the twentieth anniversary of the Britannia coin range, in 2007 a large variety of formats were issued, bearing a new reverse design - this time by Christopher Le Brun, the first artist after the original designer Philip Nathan to contribute to the series. On it, Britannia is shown seated, similar to the personification of Britannia originally used on coins of the Roman Emperor Claudius, and then on British halfpennies and farthings since 1672. It is rendered in a more Classic, detailed style.
The olive branch curving to the left of the figure is like a wreath, hence the Wreath Britannia nickname for the design.
The composition of the coin is 91.77% gold alloyed with 8.23% silver. The half-ounce (1/2oz) gold coin was only issued in Proof FDC grade in mint sets, and not individually. | 
Search for United Kingdom: Gold Half Ounce 2007 Britannia on eBay 
