PHOTO: JACKSON LEE

Paul McCartney's fiancee Nancy Shevell unveiled her sensational $650,000 engagement ring on Friday, May 6, and Life & Style has the exclusive photos!

"Nancy's ring is huge! You can tell she was excited to finally be showing it off," an eyewitness tells Life & Style. "She was glowing and relaxed and looked like she couldn't be happier. She even gave a thumbs up when asked how her and Paul were doing. Clearly the couple is very happy," the eyewitness continued.

A source tells Life & Style of the huge round-cut diamond ring, "Paul spent more than $650,000 on the gorgeous ring, and Nancy absolutely loves it!"

Life & Style originally broke the news of the couple's engagement after dating for four years. Check-out this week's issue for all of the engagement details!