This is a pretty, feminine version of the classic half-eternity band. By Marie Mas, it has pink amethyst and blue topaz set into an 18k rose gold setting. The setting itself here is the star, as noted by Moda Operandi, the site selling the ring: “Designed to turn with the body’s movements, this ring the ‘Swinging Stone Collection’ features an innovative design of topaz and amethyst set back to back and encased with 18K gold, enabling the design to rotate from pink to blue.”

This sells for USD$4,600.