Crown Emerald Diamond Engagement Ring R800-3In 18k white gold with a U set pav band and a hidden halo beneath the crown, the Crown R800 3 was built around the particular demands of a three carat emerald cut. The 0. 52 carats of G, VS round brilliants run the band and gallery in a way that frames the center stone without softening its geometry. An engagement ring where the stone and the setting were clearly meant for each other.