✨️RS vermeil is a thick layer of solid gold over sterling silver. Specifically, that layer must be at least 2.5 microns thick. RS vermeil jewelry is always crafted using 18kt gold – the highest karat offered in the market. Because of this substantial gold layer, these pieces exude a long-lasting shine and are less likely to tarnish with regular wear. Metal Purity: .925 Sterling Silver  Width: 6mm (approx.) Wearable Length: 17.5" (approx.) Weight: 35g (approx.) Designer Signed Ross-Simons Gold over 925 Sterling Silver XOXO Tennis Necklace. Features secure safety clasp.