Natural Nagura Stone for Sharpening Honing Waterstones Whetstones (12K-N45) 1.7" x 1.7" x 1.7" (45 x 45 x 45mm); 9.0 oz (256g); grit ~12000 (very fine), medium hard Natural "Ocean Blue" Tsushima nagura stone: used with full-size synthetic and natural sharpening and honing waterstones Creates a slurry (creamy paste) on the waterstone surface for sharpening knives, razors, blades, chisels and other tools Unclogs waterstone surface from metal micro shavings which inhibit sharpening; flattens the surface to eliminate the dish effect Quarried from a now closed underwater mine near South Tsushima Island, Japan; golden stamp of authenticity; limited stock