| Found this on the web: "Most Silver can be cleaned with warm soapy water. However, never use a cleaner that contains Ammonia, which will turn Silver black. Should this occur, Vinegar will reverse the effects of Ammonia. There are also commercial cleaners available but should be used with caution; always read the label. Do not put Silver in your dishwasher." Here it is mentioned again: " Ammonia will turn your sterling silver black.
Products such as Windex and standard Jewelry Cleaner have ammonia in them. . . DO NOT USE THEM!!! Problems will develop and will not clean by conventional methods if ammonia and/or a product containing ammonia has been used. Should you confront this situation, clean the jewelry with vinegar. Vinegar will not clean silver, BUT it's opposite on the PH scale and will negate the effects of the ammonia. After you clean with the vinegar, you can then clean the silver by conventional means; warm sudsy water and use a soft toothbrush, or approved sterling silver cleansers." ----------------- I would still be careful - vinegar is acidic, probably not good for sterling either. Try Silver Cleaner first, maybe that will work. | 
