BEST SELLER! Rhodium plated Alloy on waxed linen cord. Rhodium is a rare, silver-white hard metal in the platinum family. It’s resistant to corrosion and oxidation in moist air — rhodium also increases the durability. One of the biggest upsides to rhodium plating is it’s nickel free, making it hypoallergenic. Longevity can depend on ones body chemistry.