This Ohira stone is marked to the upper right Ai Renge or Blue Renge and
below that Ohira Yama or Ohira Mountain.
I found this stone to be very consistent and in the medium grit and hardness
ranges and is perfect as a bevel setting stone. I was actually able to shave
off it but the shave was not very close, yet not painful. I suggest that this is a
stone to use before your finishing stone or polishing stone. It looks very
much like fine marble with a faint green cast to the background and dark gray
to the karasu patterns which are more bold on the back. There are no cracks
in this stone and any lines you see are solid and cosmetic in nature.
The back is very flat and sits perfectly solid on a table or the 160 x 80 x
17mm size will fit almost any bench stone holder.