The Most Expensive Celebrity Engagement Rings

5. Grace Kelly Engagement Ring From Prince Rainier III of Monaco – $4.06 million

Valued at $4.06 million according to the Ruby Media Corporation, Grace Kelly’s emerald-cut diamond ring was created by Cartier. The 10.47-carat diamond ring also features two gorgeous diamond baguettes. Since it’s an important piece of Hollywood and European royalty history, the ring would probably fetch a lot more if it was ever sold at an auction.