They say three’s a crowd, but not when it comes to a girl’s best friend. Three-stone diamond necklaces — symbolizing past, present, and future — glittered on Ellen DeGeneres, Lauren Graham, and Amy Brenneman at Nov. 4’s Emmys. Drea de Matteo, Uma Thurman, and Megan Mullally have also sported the rocks, which retail from $200 to $75,000. The necklace ”is classic and elegant, but also very youthful,” says RAND Diamond’s Leon Cohen. ”You can wear it with jeans during the day or for the most sophisticated evening.” Looks like three’s company after all.