196 - Important 28.00 Carat Natural Sapphire, Diamond and Platinum Lady's Ring, Size 7. Unsigned. Very Good Condition. Accompanied by a GIA Certificate Dated Feb. 27, 2012 Stating the Center Stone Weighs 27.91 Carats and is a Natural Corundum Cushion Shape Sapphire with No Indications of Heat Treatment. Measuring 18.74mm X 16.47mm X 8.93mm. Shipping $20.00 (estimate $30,000-$40,000)