MILLSTONES, GRINDSTONES, GRINDING WHEELS AND THE LIKE, WITHOUT FRAMEWORKS, FOR GRINDING, SHARPENING, POLISHING, TRUEING OR CUTTING,HAND SHARPENING OR POLISHING STONES, AND PARTS THEREOF, OF NATURAL STONE, OF AGGLOMERATED NATURAL OR ARTIFICIAL ABRASIVES, OR OF CERAMICS, WITH OR WITHOUT PARTS OF OTHER MATERIALS