A pre-polishing lap prepares the cut facets for final polishing by removing scratches and surface damage from the cutting process. This is often the most-neglected step in faceting. An omitted or abbreviated prepolishing step assures a long and miserable time in obtaining a fine finished polish. This usally produces complaints like “My hands hurt from pressing the stone against the lap trying to get the polishing lap to polish”.
A properly prepolished stone should achive a perfect polish on the polishing lap in SECONDS, not minutes!