6804: Mill/grind stones, grinding wheels & pts of nat stone, abrasives/cera

680410: Millstones and grindstones for milling, grinding or pulping 680421: Millstones, grindstones etc of agglomeratd synthetic/natural diamond 680422: Millstones, grindstones etc of oth agglomeratd abrasives or of cerami 680423: Millstones, grindstones etc of natural stone 680430: Hand sharpening or polishing stones 6804: Mill/grind stones, grinding wheels & pts of nat stone, abrasives/cera