Demi Moore said she will always love her engagement ring from husband Ashton Kutcher the most of all her diamonds.
The Hollywood star attended the UK charity premiere of her new film Flawless - about businesswoman Laura Quinn who plots to rob the diamond company she works for - at London's Covent Garden Odeon with Kutcher by her side.
Moore said: "I love diamonds over any other stones, I'm a big fan but my engagement ring will always be my favorite."
The film - set in London in the 1960s and directed by Michael Radford - co-stars Sir Michael Caine as janitor Hobbs who helps Laura plot a diamond heist when she becomes frustrated that as a woman she is always being overlooked for promotion.
Moore added: "It was my second time working with Michael. I was actually more excited this time because I just have a greater appreciation for who he is and all he has done.
"I hope when I'm in my 70s I can be as on top of my game as he is."
