1.00 cttw Round Diamond Trinity Past, Present, Future Diamond Engagement Ring. This ring is a size 7 1/4. The center diamond is a round brilliant cut diamond with a total carat weight of 0.31 ctw. This diamond has a clarity range of SI2 with an I color. This ring also features 26 round cut diamonds with a total carat weight of 0.69 cttw. These diamonds have a clarity range of SI1 to 1I with a color range of H to I.