The Trial of the Pyx (pronounced pIks) is a procedure in the United Kingdom for ensuring that newly minted coins conform to the required standards. These trials have been held from the thirteenth century to the present day, normally once per calendar year.
In medieval times the Master of the Mint was ordered to save for trial one coin for every ten pounds of silver minted. A trial at that time was normally conducted every three months. This procedure was developed during the reign of Henry III and even with modern day technology, 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 pass the “trials”, but it has been a problem in the past—being too tempting for the Master of the Mint to not steal the coins’ precious metals.
The title of these trials comes from the Greek word for wooden box, pyx. In modern day The Pyx are reinforced (often plastic) boxes of currency ready to be assayed or tested. In them are hundreds of envelopes containing thousands of coins.The coins in 2017’s Trial of the Pyx ranged from a £49,995 commemorative coin made from a kilo of solid gold, down to a simple 20p piece.
Trials are currently (as of 2018) held at the Hall of the Worshipful Company of Goldsmiths; formerly, they took place at the Palace of Westminster. There is also a Pyx Chapel (or Pyx Chamber) in Westminster Abbey, which was once used as secure storage for the Pyx and related articles. The Goldsmiths’ Hall is an impressive temple to the yellow metal, featuring huge chandeliers, gold-leaf on the walls, and prominently displayed treasures. For the trials, members of the public and invited dignitaries are sat on one side of the room. The Queen’s Remembrancer, a judge, sits at the head of the table to give her address and start the trial.
Throughout the year, coins are selected at random from batches of each denomination struck by The Royal Mint. They are then sealed in bags that contain 50 coins each and locked away in the Pyx chests. The chests of coins are taken to the Trial of the Pyx. The Jury at each trial is made up of leaders from the financial world and at least six assayers from the Worshipful Company of Goldsmiths, who put the coins to the test. The assayers are given two months to test that the coins meet the statutory limits for metallic composition, weight and size. They test the coins against what is known as a Trial Plate, which acts as a benchmark. Trial plates are kept by the National Measurement and Regulation Office. With more than 35,000 coins to count, a lot of the work is also done behind the scenes by machines. After two months the trial reconvenes and the Queen’s Remembrancer asks the Jury for its verdict. The verdict is given every May in the presence of the Master of The Royal Mint, the Chancellor of the Exchequer, or his Deputy.
Statutory basis for the Trial of the Pyx is given by the Coinage Act of 1971, the latest in a long series of similarly named Acts of Parliament. Specific procedures are established by Order in Council, the most recent being the Trial of the Pyx Order 1998, which was amended in 2005, 2012, and 2016. It is not required for a new Order to be issued for each Trial: this is mandated (to occur) only with regulatory revision.
This age old tradition is an important step in the minting process for coins in the United Kingdom. It guarantees authenticity of all British coinage and keeps the Royal Mint accountable to their important job.