28mm Rock Chic necklace in 18k gold in sterling silver. Our sterling silver jewellery is plated in rhodium. Rhodium is a precious metal belonging to the platinum family. Rhodium improves the finish of silver and makes it more resistant to tarnishing. The base metal of all our jewellery is 925 sterling silver. Vermeil means that sterling silver is plated in at least 2.5 microns of gold or rose gold. Ours is at least 3 microns of 18k gold / rose gold which makes for a really thick coating of gold / rose gold on sterling silver.