Diamond blades are used with saws that are going to be cutting hard materials such as concrete, bricks, blocks and stones. Used in either wet or dry sawing applications, these blades are made with a metal and diamond crystal mixture. The diamond crystals provide an extremely hard grinding agent that can cut through almost anything while still maintaining their structure. Make sure to clean the blade properly to preserve its cutting potential.
Examine your diamond blade to make sure the blade isn't worn, but simply needs cleaning. If the diamond segments that were embedded in your blade are now worn down to almost nothing, you will need a new blade. Cleaning it will not fully restore an old, worn out blade. If, however, the blade is gummed up from whatever you are cutting, cleaning will help.
Find a piece of cement or concrete that is large enough to run your blade on. Make sure the piece belongs to no one and is available for this type of use.
Plug in the saw and activate the motor so the blade is rotating on full power. Make some shallow cuts into the cement or concrete. Use at least a few different angles. Ten to 20 seconds should be sufficient for cleaning your diamond blade so it works like a new saw.