Ohira Uchigumori Koppa Japanese Natural Toishi Whetstone

Approximate Dimensions/Weight:
130 mm (5.12") long × 75 mm (2.95") wide × 30 mm (1.18") tall / 392 grams (0.86 lbs).

Hardness: 3.8
A beautiful and clean Ohira Uchigumori koppa from the natural whetstone museum. This stone is perfectly sized for Kamisori and it's very firm and fine for Uchigumori. Water only honing is pleasant with light, consistent granularity and barely any self slurry. Diamond plate slurry is extremely grit rich and fast cutting with the pink slurry turning black immediately with swarf. The texture remains mildly granular and this breaks down rapidly to a high pitched whispy sound and feel.
A photo of the stone's polishing ability on a high quality Japanese kitchen knife is shown.