FACETERS: ANYONE KNOW IF THE 6" ROCK RASCAL-MODEL J TRIM SAW IS GOOD FOR CUTTING mohs 9 GEMSTONE ROUGH?
if you have a decent diamond blade on that Rock Rascal, it should cut a mohs hardness 9 gemstone just fine. Make sure you are using plenty of lube (should be oil based) and experiment to get the right amount of pressure, firm without appreciably slowing or bogging down the motor.
If it does not cut, probably your blade needs dressing or is worn out. I would not try to cut a 6 inch diameter piece on a 6 inch blade, but anything of diameter 3 inches and below ought to be fine.