Ohira Uchigumori Koppa Japanese Natural Toishi Whetstone

Approximate Dimensions/Weight:
150 mm (5.91") long × 52 mm (2.05") wide × 20 mm (0.79") tall / 312 grams (0.69 lbs).

Hardness: 3.6
A bit more Another beautiful Renge filled Ohira Uchigumori koppa from the natural whetstone museum. Perfect for hand held honing of straight razor and Kamisori. This hard stone has no impurities and is firm/fine enough to finish a razor with ease. Water only honing is mildly granular but consistent. Slurrying the stone yields a pink grit rich slurry which cuts extremely fast and removes medium grit scratches with ease. The mud breaks down rather quickly and a shaving edge is easily achieved. 
A photo of the stone's polishing ability on a high quality Japanese kitchen knife is shown.