Addison Necklace Gold by Midsummer Star. Addison Necklace Gold. When it comes to classic jewels, our Addison Chain Necklace is the ultimate piece for everyone to love. From our new unisex Two Tone Collection, this piece takes fashion and accessorising back to the very basics, but helping you stay on trend at the same time. 18k Gold Plated (1 micron thick), E-coating for a premium finish, Tarnish Resistant, Chain Length 47cm 5cm extension.