Trial of the Pyx auction

On 13–14 February, Stack’s Bowers Galleries partnered with The Royal Mint in a special auction of coins that had been tested and evaluated as part of the annual Trial of the Pyx, an ancient and rigorous evaluation ceremony with origins that stretch back over seven centuries. This is the first time these Trial of the Pyx test coins had been presented in a public auction. The top-selling item in the sale, making $78,000, was a set of two ‘Trial Plate’ 999 fine gold bars from the 2023 trial, which bear the distinctively shaped edge that serves as an anti-fraud measure (lot 1180).

The front of each bar is stamped with the monarch’s official coinage effigy – the final portrait of Queen Elizabeth II by Jody Clark and the current portrait of King Charles III, specifically taken from the 2022 sovereign coin, by Martin Jennings. At the centre of each bar was engraved the details of the bar and the circumstances surrounding its creation, which reads: ‘This standard (commixed of 999 Parts of Fine Gold and 1 Parts of Alloy in 1000 Parts by weight) was independently tested as part of the Trial of the Pyx 2023 held at Goldsmith’s Hall, London.’

The backs of these bars were hallmarked by the London Assay

Office based at Goldsmiths’ Hall, which is identified by the Leopards Head hallmark. Also featured in this unique hallmark combination are the Sponsor’s initials (‘A.J.’) Anne Jessopp, Deputy Master and Chief Executive of The Royal Mint, the traditional fineness symbol (gold), the millesimal fineness mark, the date letter mark and the King’s Head, which is a special Coronation commemorative mark.