'The Simple Life' star Nicole Richie has sparked rumours that she is engaged to boyfriend Joel Madden after being spotted wearing a large diamond on her ring finger.
According to Hollywood.com, the star was seen wearing the ring at a party in Hollywood.
A source also told the New York Post: "It was one big rock surrounded by more diamonds."
"(Madden was) overly attentive to her - keeping his arm around her all night - and repeatedly asked her if she was OK."
