The best cut for a ruby engagement ring is the one that resonates with you. Perhaps it's the regal oval cut that speaks to you, or the statement emerald cut with its beauty and sparkle. The most common cut for a ruby is a round or oval, bringing out deeper shades of red to help enhance its bold, romantic sentiment. A ruby and diamond engagement ring in either of these cuts is especially timeless, surrounding the ruby in a halo of beautiful diamonds, providing exceptional sparkle.   Coloured stone engagement rings have become popular in recent years as couples opt for something more unique that expresses their personality and love for each other—and the passionate red of the ruby has put it in the spotlight.