Three Stone Sapphire and Diamond Ring For Sale at 1stDibs Vintage Sapphire and Diamond Ring For Sale at 1stDibs Vintage Sapphire and Diamond Ring For Sale at 1stDibs Vintage Sapphire and Diamond 3 Stone Ring For Sale at 1stDibs Vintage Sapphire and Diamond Ring For Sale at 1stDibs. RESERVED A vintage 1950s three stone ring. Centre stone an ink black blue sapphire, measures 4x4mm (est 0. 30 carats). Each side a brilliant cut white diamond 3. 4mm (est 0. 15 carats) Colour H j, clarity Si. Platinum head measures 12x5mm, depth 4. 7mm. Shank is stamped 18CT PT although a little rubbed. Weight 1. 8grams. Band tests as 18 carat gold. Size N, we can resize free of charge.