A diamond pendant worth tens of thousands of dollars, once worn by former South Korean first lady Kim Keon-hee on an official trip, has become the unlikely catalyst for her fall from grace.The luxury item, and its meticulously crafted fake, are now at the centre of a criminal case that saw Kim detained late on Tuesday pending trial, accused of deception, obstruction and a decade-long pattern of alleged wrongdoing.Investigators say Kim lied about the pendant’s origin, staged a cover-up and...