If your stone removes a lot of metal then it is most likely a prepolisher, but hard to really tell, it might be best to have it tested by someone that has experience with Jnats to be sure what do you have in your hands. With Jnats there is hard and then there is hard, and the difference is the hard hard ones are polishers and the others are prepolishers.
Nagura is the type of stone, they have several different kinds.Quote:
impression that the word nagura means slurry stone, Tomo-nagura is one type, you mensioned "Nagura" What type are you referring to when you say "Nagura"?
In order of use in progression they are Botasn, Tenjio, Mejiro.