Annual Trial of the Pyx puts Royal Mint’s work to the test, in tradition dating back to 13th century

The smallest and largest coins ever minted in the UK will be weighed by the Royal Mint as part of an ancient ceremony that dates back more than 700 years.



The test will be part of the Trial of the Pyx, an annual quality assurance test to make sure that the coins being made by the mint are adhere to the benchmarks set out by the government.



At the trial, first recorded in 1282, the Royal Mint and the master of the mint, currently George Osborne, are on trial. Modern legislation does not mention penalties if the jury does find spenders are being shortchanged. But in the past punishment has included the imprisonment of the master, as Giles de Hertesbergh discovered to his cost in 1318, when he was jailed for six weeks.

Facebook Twitter Pinterest The 70,000 coins which will be tested at the trial include the largest and smallest produced by the Royal Mint. Photograph: The Royal Mint

The 70,000 coins on trial this year include the Royal Mint’s 2015 first world war gold Kilo coin, which at 100mm (4in) is the largest coin on trial, and the 8mm 2015 Proof gold Britannia fortieth of an ounce coin.

Over the last production year, one coin in every 200 commemorative ones has been kept back to be examined.



Facebook Twitter Pinterest A jury member chooses a coin to examine at the Trial of the Pyx. Photograph: The Royal Mint

Pyx is the Roman word for chest, and at the trial a jury of City of London liverymen from The Goldsmiths’ Company, one of the oldest hallmarking companies in the UK, is presented with “pyx packets” taken from chests.

From these packets the examiners select one coin at random and place it in a ceremonial copper bowl in front of them. The trial is then adjourned to allow time for these coins to be tested by the Goldsmiths Assay laboratory and the National Measurement Office, and the verdict will be announced in May.

Facebook Twitter Pinterest Jury members examine coins at the Trial of the Pyx. Photograph: The Royal Mint

Beside the copper bowl each jury member has a ceremonial wooden bowl, into which the remainder of the coins will be placed and these will be group weighed at the ceremony.

Although no longer likely to end with a jail term, Adam Lawrence, deputy master of the mint, said the trial was still relevant in modern times.

“The Trial of the Pyx is one of the oldest quality assurance trials in existence and is as important today as it has ever been, helping ensure integrity and confidence in our UK currency, commemorative and bullion coins,” he said.