To bring your diamond ring back to life, soak it for about 20 minutes in a dish filled with warm water and a few drops of dish liquid. Now, go over it with a clean, soft toothbrush or bottle brush and rinse. Don’t regularly use ammonia. While it will add sparkle to your diamond, repeated use can cause discoloring to the metal. Instead just add a tiny splash of ammonia to a small bowl of water. Using a brush, go over the diamond, rinse, and pat dry.