1.5 Carat Old European Diamond Engagement Ring Platinum. This superb Art Deco engagement ring features a 1.58 carat Old European cut diamond set in platinum. The shoulders of this ring are designed with adorable loops of open space that are connected with a polished piece of platinum, creating an almost braided look. Connecting the raised section of the shoulders to the band below are small circles, which add a nice dimension to the side profile. From every angle this is a fascinating ring to stare at and appreciate fine craftsmanship.