Sterling Silver Round White Cubic Zirconia Stud Earrings White Cubic Zirconia Oval Charm Earrings - in Sterling Silver - FREE gift-ready jewelry box ::: [ Potential Enhancement Methods: cubic zirconia ] - Synthetic. Some are covered with a product that makes the stone more durable. ::: [ Care and Handling: cubic zirconia ] - Clean with warm soapy water and a soft cloth. :::