Sheffield Assay Office has scored an innovative ‘first’ that will boost its business and allow coin collectors, commemorating the Royal Wedding, to ensure it is a 22 carat affair.
The organisation, formed nearly 240 years ago to guarantee the content of all products made from precious metals, has become the first to be allowed to hallmark coins.
The Office has teamed up with commemorative coin specialist the Commonwealth Mint to enable “proof” coins to be struck, which carry the Office’s hallmark and yet remain legal tender.
The first hallmarked commemorative coins - a limited edition of 1,000 - will be made on the day of the Royal Wedding and will show Prince William and Kate Middleton in profile on the side bearing the hallmark, with the Queen’s head on the other side.
The 22 carat gold coins are legal tender because they are issued on behalf of Tristan da Cunha, the remote group of volcanic islands in the South Atlantic, which is a British overseas territory.
Coins cannot normally be hallmarked because that involves removing a sample for testing and then striking the Assay Office’s mark, changing the coin’s appearance. Either action would stop the coin being legal tender. What’s more, proof coins are produced in such a way that all the fine detail is visible, while the background has a mirror-like finish, which would be marred by the hallmark.
Following an approach from the Commonwealth Mint, the Assay Office came up with the answer to the hallmarking conundrum.
“The solution is to put the hallmark in the die, but we have to pre-test the metal on the day and supervise the striking of the coins. After that, we take possession of the dies,” says Assay Master Ashley Carson.
Once it came up with the solution, the Assay Office had to win approval from the British Hallmarking Council, which gave the go-ahead for the innovative new hallmarking process.
“This is a really good ‘first’ for Sheffield and a good opportunity for the future,”says Mr Carson, who can see more opportunities for hallmarking commemorative proof coins as the 2012 London Olympics apprach.
Commemorative coins are very big business, says Mr Carson, with limited editions of proof coins that are legal tender being particularly attractive to collectors, so becoming the first Assay Office ever to win approval to hallmark them opens the way to an important new source of business.