.A 6.45-carat emerald-cut sapphire with a deep navy-blue color anchors this 18-karat white gold ring. Four corner prongs frame the center stone, while a halo of round diamonds follows its clipped corners. Matching round diamonds extend down the slender shoulders, bringing the total diamond weight to approximately 2.40 carats. The sapphire is accompanied by a GIA report indicating heat treatment. Ring size 6.25.