Mood of The Day: Diamonds Are A Girl’s Best Friend February 13, 2015 By Mariella in Mood of the Day Tags: diamonds, diamonds are a girl’s best friend, fashion, Harry Winston, jewellery, jewelry, Marilyn Monroe, pink Leave a comment The beautiful and iconic Marilyn Monroe. The song “Diamonds Are A Girl’s Best Friend” was sung by her in the movie Gentlemen Prefer Blondes.