Soak your Elsa Peretti® 18k gold necklace in the Tiffany jewellery cleaner solution. After two minutes, remove the jewellery from the solution using tweezers. Using a soft, fine-grained brush, gently brush between the back and crevices of the jewellery to remove any dirt or residue. Rinse it, then gently dry and polish it with a Tiffany polishing cloth. If you bring your Elsa Peretti® Open Heart necklace to the store, you may request a professional cleaning service instead.