Trial of the Pyx Trial of the Pyx The Trial of the Pyx () is the procedure in the United Kingdom for ensuring that newly minted coins conform to the required standards. These trials have been held from the twelfth century to the present day, normally once per calendar year. The form of the ceremony has been essentially the same since 1282 AD. These events are trials in the full judicial sense, presided over by a judge with an expert jury of metallurgical assayers. Given modern production methods, it is unlikely that coins would not conform, but this has been a problem in the
Coins of the pound sterling coins was reduced from 92.5% to 50%, with some of the remainder consisting of manganese, which caused the coins to tarnish to a very dark colour after they had been in circulation for long. Silver was eliminated altogether in 1947, except for Maundy coinage, which returned to the pre-1920 92.5% silver composition. The 1816 weight/value ratio and size system survived the debasement of silver in 1920, and the adoption of token coins of cupronickel in 1947. It even persisted after decimalisation for those coins which had equivalents and continued to be minted with their values in new pence. The UK