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.
Britannia coins belong to an extensive range of British bullion coins issued by the Royal Mint in gold since 1987 and in silver since 1997. The range has a "definitive" Standing Britannia design issued every year as bullion (such as this coin), and a series of one-year types issued as collector proofs only.
The mint says about the coin:
Britannia has represented a nation and its people since Roman times and more than two thousand years later the icon is still instantly recognisable on a bullion coin.
Designed by the team behind the United Kingdom’s 12-sided £1 coin, known as "the world’s most secure coin", the Britannia 2024 bullion coin features four innovative security features that make it one of the most visually secure coins in the world. Surface animation provides a background for Britannia, reflecting the flow of waves as the coin is moved, and between this and the banding of the coin you will find micro-text with the wording "Decus et Tutamen", which translates as ‘"An ornament and a safeguard" and describes the features that both decorate and protect the coin. A latent feature in the lower-hand segment of the coin switches between a trident and a padlock based on the viewer’s perspective - emphasising her maritime strength and the coin’s secure nature - and details such as the Union flag on Britannia’s shield have been specially highlighted with tincture lines. | 
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