A classic mizu water blue tomae fron the Ozuku mine. This stone is very hard although it makes a very nice platform for Mikawa naguar, tomo nagura or a diamond plate generated slurry. I found the best way to use it, after a 5 or 8k synthetic is to run about 30 passes on a tomonagura slurry and then add one layer of Kapton tape on the spine and add an additional five or six weight of the razor stones. These land right on the edge of the edge and it can kick up the edge to 15k or higher.
A very handsome stone it has a faint cloudy or foggy pattern. There are not inclusions for cracks although at both extreme ends of the top surface the sediment lays slightly bias.
Hardness 5+ / Fineness 5+
Cutting speed 4- to 4+ with tomo, 5- with diamond plate slurry
I test all of my stones with Henckelso Friodur unless otherwise stated.
Your results may vary depending upon your skill or type of steel.