By Jeremy Hodges and Kit Chellel

Bloomberg News

LONDON — Britain’s coins go on trial every year before they end up in the nation’s wallets and cash registers. Last week, as they’ve done since the Middle Ages, a panel of experts handed down their verdict after six weeks of checks.

Chancellor of the Exchequer George Osborne was among those at the Goldsmiths’ Hall in London on May 2 to watch the trial come to an end. If no one took much notice, it was perhaps because the coins haven’t failed the test in a few hundred years.

The Trial of the Pyx is one of Britain’s oldest and strangest legal procedures. It’s a mixture of a court case, an industrial-quality check and a marketing exercise for the Royal Mint, Britain’s official coin maker.

After this year, the procedure, named after the Latin word for chest, will have a new object to scrutinize. In March, Osborne announced that Royal Mint would create a new one-pound coin to help reduce counterfeiting. It will have a twelve-sided angular shape, unlike the smooth outline of the current version, and will have special technological features that, the Royal Mint says, will make it the world’s most secure coin.

The Trial of the Pyx began in February at the Goldsmiths’ Hall, an ornate room lit by six car-sized chandeliers. Nick Harland, a deputy clerk with the Goldsmiths’ Company, explained to an audience of about 100 people how the jurors would examine about 46,000 coins from Britain and New Zealand.

“This is essentially the Royal Mint’s big day in the sun,” Harland said. “What we are testing for here is precious metal content, and the weight, size and shape.”

The coins ranged from piggy-bank fillers to a one-kilo gold coin valued at 50,000 pounds ($85,000), commemorating the birth of the newest member of the British royal family, Prince George.

The Pyx jury is overseen by the Queen’s Remembrancer, the oldest judicial position in the country. Currently it’s Master John Leslie, who on the opening day in February sat at the head of a long table wearing a black robe with frilly white cuffs and a tricorn, a three-pointed hat.

There used to be several different types of jury, Leslie said. Grand juries, still used in the U.S., were British “men of worth, ingenious and learned” and would try the most important cases. They were mostly abolished in 1933 in the U.K.

Special juries made up of merchants, farmers, cooks or fishmongers began being commonly used in the 1600s to deal with cases with a technical aspect. By the 19th century they were infrequently used, Leslie said, as specialist knowledge came to be seen as something that should be provided by experts, not jurors.

In 1971, the Coinage Act resurrected the practice for one type of case only: the Trial of the Pyx.

After Leslie’s speech, the jurors placed a few of the coins in bowls to be taken away for chemical tests to ensure the correct composition of gold, silver, platinum, copper nickel or zinc, before moving into another room full of counting machines to log thousands of general circulation coins. That concluded the public part of the day, with the remaining tests taking place behind closed doors.

No one seemed to know what would happen if the coins didn’t pass muster.

“That hasn’t happened in a really long time,” said Tom Almeroth-Williams, the communications officer for the Goldsmiths’ Company. “The Royal Mint has very stringent standards.”