Antiques Roadshow guests are often surprised to hear an item that’s been gathering dust in their home for years is actually worth a fortune. In last week’s episode of the BBC favourite, one guest left expert Joanna Hardy and the crowd gathered baffled as she revealed where a valuable brooch had been left, almost forgotten. Fine jewellery specialist Hardy was impressed by the sparkling item brought to her in last Sunday’s programme. “When I see this, I just think, ‘it is magical,'” she commented, beaming over the brooch. “It is a beautiful piece of jewellery. Please tell me how did you get this…