Synthetic diamond micropowder is a new type of ultrafine superhard materials(finer than 320#), It is produced in large quantity and is not expensive At present, it is widely used in machinery, aviation and space, optical instrment, glass, ceramics, electronics, petrleum, geology, military industry and other industrial sections. It is an ideal material for lapping and polishing such hard materials as cemented carbide, ceramics, gems, optical glass. Generally, W0-0.5 to W6-12micropowder is used for polishing, W15-10 to W22-36for lapping. W12-22and coarser for finishing.