Stepped Art Deco Diamond Engagement Ring in PlatinumStepped Art Deco Diamond Engagement Ring in Platinum. This . 75 Carat old European cut antique engagement ring is one of our favorites. The center diamond is prong set with v shaped corner prongs creating a square appearance. The low set center diamond is accented with round diamonds creating a square halo. The platinum setting features twenty two (22) round cut diamonds and gives this ring an immense presence with a total diamond weight of 1. 08