Abstract: The present invention relates to a method of producing a diamond surface including the steps of providing an original diamond surface, subjecting the original diamond surface to plasma etching to remove at least 2 nm of material from the original surface and produce a plasma etched surface, the roughness Rq of the plasma etched surface at the location of the etched surface where the greatest depth of material has been removed satisfying at least one of the following conditions: Rq of the plasma etched surface is less than 1.5 times the roughness of Rq of the original surface, or Rq of the plasma etched surface is less than 1 nm.