'If it isn't jet black, then put it back!' Eric Knowles gets some expert advice on telling the difference between original and replica Whitby jet. The seaside town of Whitby saw a boom in the production of the organic gemstone in the 1830s, before Queen Victoria famously wore it as mourning jewellery. Meanwhile, in County Durham, two teams of mums and daughters scour the stalls of a salvage and antiques fair for collectibles to sell at auction. Janet and Amanda are 'looking for hidden treasures', while Debra and Jade are hoping to 'find that needle in a haystack'. With £300 to spend, Amanda spots a stall of plaques displaying car logos, but her expert Colin Young steers her away from them. Over with the blue team, Jade likes a black forest carved fish, but she decides to throw it back. Can auctioneer Caroline Hawley hammer out profits for both teams in the sale at Beverley Racecourse?