‘The gold in this vault never leaves’: secrets of the Royal Mint

have the gold old you asked for,” says the he security guard as I arrive at the Welsh sh home of the Royal Mint – Britain’s ancient coinmaking and gold storage institution.

It is five years since the Mint launched its “precious metals” division, allowing investors to buy its gold. old. For those unable to afford a full-sized gold bar – worth around £400,000 at today’s prices – last month it also launched ed an exchangetraded commodity (ETC). This is a listed fund that allows investors to buy small quantities of gold.

For someone with £100, the size of gold is about the same as a micro Sim card in your phone. An ounce, the standard measure for gold, is rather underwhelming (see picture). It is a small solid square not much bigger than three 20p pieces, but would set investors back more than £1,000 to buy. The larger bar is worth £40,000.

I ask the guard whether I could see the main vault itself, where all the gold is kept, including a portion of Britain’s reserve as well as all the gold bought by private investors. He is impervious to my charms, and isn’t forthcoming. “I know exactly where it is and how much gold is in that vault but I’m not telling you anything,” he says.

However, he does reveal that, once a gold bar is added to the vault, it stays there forever – it is never removed. There is also a safety deposit box scheme for th those who want to store thei their own gold at the Mint – but you can’t just jus leave anything in your y box. Throughout history, con artists have tried their hand at counterfeit gold. Chancers would cut up genuine g gold bars, hollow ho them out and fill them with copper. Today, Toda background checks a are made on both the gold and th the owners before it can enter a safet safety deposit box. Gold isn’t the on only reason I’m out here in the Glamorgan countryside. The Mint is the largest coin maker in the world, producing currency for more than 30 countries last year. As I pass through security, handing over my phone and passing metal detectors, I am given ear plugs to protect me from the deafening noise. Around 1,800 of each batch of new coins are kept aside for testing. Known as the “Trial of the Pyx” and held once a year, a jury randomly selects coins from each batch for testing. The trial has taken place since 1282, when people would clip bits off the side of coins to melt down and make into new fake coins. “In previous centuries, hands have been amputated if coins were found to be flawed or incorrectly minted,” the guard tells me. As I look around a room coining £200m of coins piled high on pallets, I decide against sliding any souvenirs into my pocket.

The year of the first Trial of the Pyx, which checked the quality of coins

An ounce of gold (right) costs £ 1,000, while a larger bar (middle) will set you back £40,000