Like many other mints, the Royal Mint issues bullion coins in precious metals, having much higher intrinsic value than their face value. Most of these by tradition are measured in troy ounces of fractions thereof, but the mint also introduced metric coins measuring one kilogram of pure metal, then also two and five kilograms (they are actually fractionally heavier as a whole, to account for the small amount of other metal in the alloy), and finally in 2020 a seven kilogram coin.
The 7 kg gold coin is denominated as Five Thousand Pounds (£7,000), although the intrinsic (bullion) value is much higher than the face value.
The coins are legal tender but are not intended for circulation. They are targeted at collectors who appreciate the special editions as pieces of art or show pieces.
This commemorative gold proof coin celebrates the Platinum Jubilee (70th anniversary) of Queen Elizabeth II's reign. It features a special equestrian portrait of the Queen on the obverse, created for the occasion, showing her in her role as Head of the Armed Forces.
On the throne since 6 February 1952, at the date when the coin was issued Queen Elizabeth II was the longest-lived and longest-reigning British monarch, the longest-serving female head of state in history, the oldest living and longest-reigning current monarch, and the oldest and longest-serving incumbent head of state.
The Royal Mint issued a large variety of coins for the occasion, including this unique very large 7-kilogram gold coin.
The Royal Mint’s special release was designed by esteemed coinage artist John Bergdahl featuring a regal design befitting the longest-reigning monarch in British history. The reverse side depicts a crowned EIIR cypher surrounded by roses, daffodils, thistles and shamrocks, representing the United Kingdom. On the obverse side of the coin, a special commemorative design depicting The Queen on horseback is engraved on the precious metal. Inspired by the 1953 coronation crown coin created by Gilbert Ledward RA and the 2002 Golden Jubilee crown by Ian Rank-Broadley FRBS, the equestrian design has been created especially for the commemorative Platinum Jubilee collection.
The production and design of this piece required hundreds of hours of craftsmanship and utilized state-of-the-art engraving and laser technology. Instead of being struck on a press between two dies like a traditional coin, the details of this piece were cut into a solid gold ingot by a high-speed precision computer numerical control (CNC) engraving machine. The gold ingot originally began at a weight between 9 and 10 kilograms before being machined into the 7 kilo finished product over several weeks.
The master craftsmen at The Royal Mint closely inspected the ingot for quality before positioning it in the CNC machine, which was programmed with unique parameters to properly scale the design to this massive format and achieve the technical and aesthetic requirements intended by the designers. It took 3 to 4 days to engrave each side, after which the design was further hand finished over 2 days to remove imperfections and enhance key elements. As a final step, the surfaces were then hand-polished to a high luster over 2 to 3 days before the coin was set into its acrylic mount and oak display case, both of which were produced in the UK. | 
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