In her first appearance since secretly marrying her partner Dalton Gomez, 25, singer Ariana Grande, 27, showed off her huge engagement ring on stage in California.The unusually styled engagement ring features a huge tilted oval shaped diamond set next to a pearl on the band and is estimated to be worth an incredible $750,000.The pop sensation appeared on stage alongside The Weeknd at the iHeartRadio Music Awards on Thursday to the surprise of the audience.