Thread: Jnat query

Originally Posted by luckypip

Does any of this give any indication of its hardness rating ie is it a medium, course or fine stone ?

Those stamps are used then the seller has no clue where the stone comes from.
No indication of hardness, it could be really soft or super hard, Japanese do not use stamps to indicate hardness, as every rating system is based on the individual seller idea of what soft and hard are.

Do you possess that rock?
If so, give it a go, it's the only way to tell what it can do.

Flatten it so you know it's dead flat and has a clean surface and then try some different steels on it, may it be razors, tools or kitchen knives.