i’ve bee buying the china made laps,they have more diamond and are very cheap compared to u.s.a. made. i teach faceting and we use whatever grit size to form our stone then true it up for polish on 1200. we use the batt TIN lap or other TIN laps to polish on. we use VERY slow speeds, about 100rpm to polish and use a good grade of 50,000 diamond powder. applying with a finge to the lap with an extremely SLOW drip of water enough to keep it a muddy slur. i just finished the cutting and polishing of a 206.95 carat pink laser YAG, 8 to 8.5 in hardness with very little problem. i use this same on topaz, spinel,garnet, sunstone, and a quartz egg about 450 carats and most all stones. we use this same lap and diamond system on everything, and all sizes, on 8 different make faceting machines. gemmakermz@cs.com