Ross-Simons - 18kt Gold Over Sterling Byzantine Center Necklace. 18". A fresh take on the traditional Byzantine necklace, our handcrafted 18kt yellow gold over sterling silver design gracefully drapes the neckline, showcasing the signature links at the center of a cable chain. An easy way to instantly look fashionable and polished! Includes 2" extender. Lobster clasp, 18kt yellow gold over sterling silver Byzantine center necklace.