The men in the workshops told me stories about the master craftsmen who once worked in Hatton Garden. “We had one old Jewish chap I used to sit next to, called Lapidus,” said Dave Harris, a former diamond-cutter, “who had been born in Russia in about 1860. He ran away from home and got apprenticed in Germany, earning nothing. He told me he used to lodge in a room with just a bed and a chair and live on bread and water. In the 1900s he moved to Paris and became a master jeweller and in the 1920s he moved to England. He was in his late seventies when he came to us. He worked piecework, so his wages never came to more than three pounds a week, but he made the most exquisite pieces of jewellery I’d ever seen, which often took him up to three months to make. The most beautiful thing I saw him produce was a rose-shaped diamond brooch, set in 18-carat gold, with enamelled petals, covered in precious stones and diamonds, commissioned by a Russian princess.”

In those days every pearl that ended up in a British jewellery shop, every precious stone, every diamond, rough or cut, came through Hatton Garden. Today the majority of the jewellery sold in the street is either cast or imported. A few of the master craftsmen remain but when they die, their knowledge will be lost.