There is a difference between a pure waterjet nozzle and an abrasivejet nozzle. With the abrasivejet nozzle, an opening in the side of the nozzle allows for the introduction of the abrasive to the high-pressure water stream. The two are mixed in a mixing tube and then exit the nozzle. With a pure waterjet nozzle, there is no opening and no mixing tube and the high-pressure water is directed to the material after it exits the jewel.