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, five and seven kilograms (they are actually fractionally heavier as a whole, to account for the small amount of other metal in the alloy), and finally in 2021 a ten kilogram coin.
The 10 kg gold coin is denominated as Ten Thousand Pounds (£10,000), 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.