PS members don't actually sell jewelry on PS. The "pre-loved" forum is a place where they can let other PS'ers know that they have jewelry available for sale elsewhere on the web. Some of the sites PS'ers use to sell their jewelry include diamondbistro.com, loupetroop.com, and Ebay. Some also list their jewelry with vendors such as Jewels by Erica Grace and Good Old Gold. As ruby59 mentioned, be sure to read the Pre-loved forum policies.