Vintage 18K gold .30 carat Old European Cut diamond stationary necklace

A .30 carat Old European Cut diamond in a floating bezel stationed on a gold chain. The diamond is set in 18K two-tone gold: yellow gold on the underside and gallery and white gold framing the stone. The concentric circles give a floating effect that was popular in the Art Deco Era. Worn migraine details. This diamond and setting came to us in a ring, but the shank was damaged so we decided to reimagine it as a necklace. We made the 14K chain adjustable at 18" and 20". Measurements: 18" and 20" stations, 2.5g Diamond details: .30 carat Old European Cut diamond, SI2/I Era: Diamond 1930s, chain modern