.81 Old European Cut Diamond Engagement Ring in Platinum. 81 Old European Cut Diamond Engagement Ring in Platinum. This dynamic Modern engagement ring features a . 81 carat old European cut diamond and Round Brilliant accent diamonds finished in platinum. The glittering center diamond is nearly colorless, set in a bezel with fine milgrain details. Thirty one (31) . 015 carat Round Brilliant cut diamonds wreathe the center stone on the face and shoulders for added brilliance. All of the diamonds have an