Pearls are the most chameleon-like of jewels: they can sell for millions or for just a few dollars, they have been used to symbolize both chastity and debauchery, they have been conspicuously worn by men and women. The production methods of both cultured and natural pearls have been fraught with controversy and their position as fashion and status symbols has waxed and waned over the centuries. Bridget Kendall discovers the social history of pearls with jewellery historian Beatriz Chadour-Sampson and Pittsburgh University professor Molly Warsh. Plus jewellery writer Victoria Finlay puts to the test one of the more colourful claims about what is in essence an iridescent blob of nacre: that if you drop a pearl in a glass of vinegar it will quickly dissolve. (Photo: Pearls in a shell. Credit: Greg Vaughn/VW Pics/UIG/Getty Images)