We use 14k gold filled metal. Gold filled means that there's a thicker layer of gold that is bonded with extreme heat and pressure to the jewelers brass core of zinc and copper. The difference between gold filled jewelry and gold plated jewelry is the gold is more permanently bonded to the metal core, making it extremely difficult for the gold layer to wear down. Gold filled metal very rarely turns your skin green. We recommend against cleaning your gold filled jewelry with harsh jewelry cleaners, instead clean with a microfiber cloth and/or soap and water. Your Gold filled jewelry can be worn in water.