Something extraordinary happened in central London recently: a host of celebrities, from Sting to Sharon Osbourne, opened their jewellery boxes to the public. The occasion was an exhibition at Browns South Molton Street called My most treasured . . .

And the objects ranged from a purely sentimental piece lent by Paul Smith to earrings from Trudie Styler that required a security guard. As a group, says Joan Burstein of Browns, the jewels showed that "it's what a piece means to someone that makes it priceless to the owner". Jewellery is not just about carats, but emotion.