Thank you for viewing. This is Iyo stone from Ehime Prefecture. Size: Weight: 1430g Width: 9.8cm Length: 19.5cm Thickness: 3.1cm Hardness: Normal. The second photo is the back side. The third photo shows the stone wet. Grain size: #2000 or higher. Photos of polishing marks are included (polishing marks from synthetic stones #1000 / #2000 are from the Cerax). Polishing method: Polish SS400 steel with a synthetic stone #1000, then polish for about 2 minutes. Magnification for photography: 120x. I think it will finish quickly and beautifully if you use it before finishing. Polishing after producing mud with an Atoma will be very efficient. As a service, I will include about 3 pieces of Iyo stone scraps (over 500g) like the ones in the last photo. They can be used as nagura stones to produce mud for polishing. They are also convenient for removing rust, etc.