Royal Mint - 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 required standards. The trials have been held since the twelfth century, normally once per calendar year, and continue to the present day. The form of the ceremony has been essentially the same since 1282. They are trials in the full judicial sense, presided over by a judge with an expert jury of assayers. Trials are now held at the Hall of the Worshipful Company of Goldsmiths, having previously taken place at the Palace of Westminster Given modern production methods, it is unlikely that coins would not conform, although this has been a problem in the past as it would have been tempting for the Master of the Mint to steal precious metals.

The term "Pyx" refers to the boxwood chest (in Greek, πυξίς, pyxis) in which coins were placed for presentation to the jury. There is also a Pyx Chapel (or Pyx Chamber) in Westminster Abbey, which was once used for secure storage of the Pyx and related articles.

Coins to be tested are drawn from the regular production of the Royal Mint. The Deputy Master of the Mint must, throughout the year, randomly select several thousand sample coins and place them aside for the Trial. These must be in a certain fixed proportion to the number of coins produced. For example, for every 5,000 bimetallic coins issued, one must be set aside, but for silver Maundy money the proportion is one in 150.

The jury is composed of Freemen of the Company of Goldsmiths, who assay the coins provided to decide whether they have been minted within the criteria determined by the relevant Coinage Acts.