Depp's new fiancee was spotted showing off her large diamond accessory for the first time as she watched him perform at a private charity event in Anaheim, California, reported E! online.
Celebrity jewellery expert Zaven Ghanimian said, "This looks like a 5-carat ring. If we assume it's a white oval diamond in the five carat range, the price would be between USD 78,000 to USD 100,000."
The blonde beauty, who hid the ring from photographers last week, is likely to have helped Depp choose the ring as a source previously revealed that Heard 'calls the shots' in her relationship with her 'The Rum Diary' co-star, whom she began dating in 2012.