Round Brilliant Diamond & Ruby Halo Engagement RingRound Brilliant Diamond Ruby Halo Engagement Ring. This sparkling engagement ring features a . 48 carat round brilliant cut diamond with . 28 carats of french cut rubies and is set in platinum. The primary stone is surrounded neatly by the ruby halo which is just interrupted by two accent diamonds sheathed in milgrain detail. The bezel set diamond sits relatively high above the shank with nice open work on the sides of the basket.