I love my turquoise Yves Saint Laurent "Arty ring" (it was still Yves Saint Laurent when I bought it – and it was sold out almost everywhere), my initial doubts wether it might merely be a temporary trend piece ended in smoke. It's a modern classic! And, believe it or not, you can currently get it for 50%/60% off in the Net-a-Porter sale. In red, turquoise, and blue. Hurry hurry.