Estate Platinum Sapphire And Diamond RingEstate Platinum Sapphire and Diamond Ring. This absolutely stunning art deco platinum ring features 7 old European cut diamonds, and 4 triangle cut sapphires. The largest diamond is in the center is approximately 3. 8mm (. 20ct) and has 2 3. 3mm (. 12ct) diamonds to the north and south. At the widest point, this elongated sapphire and diamond ring is 20. 9mm long and 14mm wide, and has a dainty 1. 1mm narrow band. This ring is a size 7, and G SI1