These are sterling silver necklaces with rhodium plating. Rhodium is a very expensive metal in the platinum group. It is even more expensive than platinum. Rhodium is non corrosive and because of that it doesn't tarnish. It doesn't react to body sweat. it is also much harder than sterling silver and hence it doesn't easily scratch.
We carry rhodium plated sterling silver necklaces in snake, cable, pop corn, box style chains.