3 Carat Cushion Diamond Sapphire Halo Engagement Ring.  This modern engagement ring features a 2.99 carat cushion cut diamond with .60 carats of sapphire accents and is set in platinum. The stunning center stone is bezel set with very fine milgrain detail and surrounded by a halo of channel set sapphires. The lovely Art Deco style setting makes great use of the color contrast between the sapphire and diamond. This ring exudes elegance and is the kind that will be passed down for generations.