Abstract: A method of CMP includes providing a slurry solution including ?1 per-compound oxidizer in a concentration between 0.01 M and 2 M with a pH from 2 to 5 or 8 to 11, and ?1 buffering agent which provides a buffering ratio ?1.5 that compares an amount of a strong acid needed to reduce the pH from 9.0 to 3.0 as compared to an amount of strong acid to change the pH from 9.0 to 3.0 without the buffering agent. The slurry solution is exclusive any hard slurry particles or has only soft slurry particles that have throughout a Vickers hardness <300 Kg/mm2 or Mohs Hardness <4. The slurry solution is dispensed on a hard surface having a Vickers hardness >1,000 kg/mm2 is pressed by a polishing pad with the slurry solution in between while rotating the polishing pad relative to the hard surface.