a lot of buffing questions stem from your perspective as to what you are looking for, IE increased value, or aesthetics. Me personally, I have only had 3 large marbles either polished or buffed. A small sulphide so beat you couldnt see inside- turned out to be a number 3, a swirl that looked like the moon x 100, and another large swirl that was completely frosted over - this one I only hit it with a low grit just so I could see the colors/patterns.