Put a few drops of liquid dish detergent in a bowl of warm water

Mix gently. Though ordinary tap water will work fine, for even better results, you can use sodiumfree seltzer water or club soda. The carbonation in these liquids can help loosen accumulated dirt and debris. Dont use hot or boiling water, especially if your jewelry contains fragile precious stones. Some precious stones, like opals, can crack if subjected to rapid and drastic temperature changes.