Mid-Century Emerald Cut Sapphire Ring with Diamond in 18KMid Century Emerald Cut Sapphire Ring with Diamond in 18K. This magnificent Mid Century ring features a 1. 03 carat emerald cut sapphire with diamond accents in 18 karat white gold. The sapphire is bezel set with milgrain detail and tapers just so slightly down to the shank with more milgrain holding the pave accent diamonds. The amazing cobalt blue of this vintage sapphire is a real sight to behold.