For 2018 the Royal Mint released a very Limited Issue Britannia £25 Twenty Five Pound Platinum Proof Coin struck in solid fine 999.5 Platinum weighing one quarter of an ounce of fine pure Platinum.
The reverse designed by David Lawrence features a traditional depiction of Britannia, channeling spirit of Ancient Rome, while the obverse features the Fifth Portrait of Her Majesty Queen Elizabeth II by Jody Clark.
These legal tender coins have been struck to proof quality using specially prepared dies and highly polished blanks.