This wasn't the standard marble lapping tile, this was a 3x8 ceramic trim tile with some enameled glaze, and had lots of texture on it. But it was the right size, and it was cheaper than buying a circular saw and a masonry blade and cutting up a marble lapping tile. Except for the hours of lapping - In retrospect getting the #@$& saw would have been worth it, though Kieth's system would have been better still. Actually it was three tiles, one for boron carbide, one for chrome oxide, and the last one was originally gonna have .25 diamond but I've just wrapped newsprint around it instead.