In the late 1820s, the British Royal Mint produced several trial coins as part of experiments on the use of platinum in coins. One of these coins has the same diameter as a farthing and a weak relief owing to the high hardness of platinum. The 1812 Pattern 9 Pence Bank Token (S3773A) was used for the obverse and the farthing of 1825 for the reverse parts of this coin. No dies were manufactured for these experiments, so expired dies of the corresponding coins were used instead. Coins minted using dies from two different coins are called mules. The coin bears the year of 1825, but was likely printed at a later date. Like all test coins, the platinum farthing has a high historic and numismatic value. This coin is also interesting because it features the portrait of the already deceased monarch George III (1738–1820).