Antique Art Deco Diamond Engagement Ring in PlatinumAntique Art Deco Diamond Engagement Ring in Platinum. This antique engagement ring is simply spectacular and has been restored to like new condition. The center diamond is a . 36 old European cut diamond, set onto a bed of diamonds. Forty two accent diamonds adorn the ring and provide a dazzling appearance from every angle. Negative space allows light to dance throughout and enhances the glitter affect of the diamonds.