2018. 3. 3. · You can pass the ring through running water once. Dry with soft cloth. Points to Remember for Garnet Jewelry. Do not use toothpaste to clean garnet. Toothpaste is good for silver cleaning but not good for garnet. It can. Garnet is one of the easiest materials to bring to a super-bright polish in a rock tumbler. But, before you get excited, here is the really bad news -- almost all garnet is below tumbling grade. The key to tumbling garnet is not in the procedure. It is in buying or collecting rough that will perform well.