... is with smooth crystal face,high compression strength synthetic diamond 1.Usage:lapping, grinding and polishing of optical objects, magnet ... polishing of optical objects, magnet heads, gems and electroplated articles. Diamond micron powder :Grit:0-0.5, 0-1, 0.5 ... -40, 30-40, 40-60 ,50-70 ,60-80 Synthetic diamond RVD: 30/35,35/40,40/45,45/50,50/60 ...