A diamond sparkles because of the way light passes through it. However, oil, sweat, and dirt can block the passage of light. Thus, unless you clean your diamonds regularly, you cannot expect them to sparkle as they should. Diamonds are easy to clean. All you need is warm water, a soft toothbrush, and mild soap. Do not use toothpaste to clean diamonds. Soak your diamonds in soapy water for a few minutes and gently clean them with a soft-bristled toothbrush. Along with the face of the diamond, also clean the back where dirt is easily accumulated. You can then wipe it dry with a soft, lint-free cloth. If you are cleaning your diamond jewellery in the sink or wash basin, make sure that you have blocked the drain before you start. Ideally, diamonds should be cleaned once a fortnight. Do not use any chemicals to clean your diamonds. This can erode the metal prongs or even dissolve it.