All metal parts are made of nickel-free brass. Chain length 17,5 inches Brass jewelry will oxidize over time with everyday wear and exposure. A gentle rub with a polishing cloth will bring its shine back. Avoid continuous contact with water, chemical lotions, and perfumes. You can immerse your precious jewel in a bubble bath once in a while to remove any residue, however, please ensure you dry it completely with a soft cotton cloth or a polishing cloth. Always store your jewels in a clean and dry place.