Vintage Petri Deco Diamond Cocktail Ring in Platinum This incredible Art Deco platinum cocktail ring features an amazing arrangement of Old European and Single Cut diamonds. The total diamond weight of this ring is 2.27 carats which is spread across asymmetrical split shanks and a line of three (3) larger Old European diamonds bisecting the open space. There is also fine milgrain detail on the platinum surrounding the smaller Single Cuts on the shoulders.