This suita strata awasedo is a totally unique and remarkable stone. Being
from a shallow suita strata it is only moderately hard, and with a plane blade
it will relinquish a slurry with only clear water. The cutting speed is very fast
and the black ultra fine very even goma or seasame seed pattern may be a
contributing agent. There are indications of a namazu pattern at one end as
you can see. The back is flat and sits perfectly solid on a table or you will find
that the 193 x 74 x 30mm size will fit almost any bench stone holder.
A moderately hard stone that will slowly give up a slurry with just clear water
or if it is used with a diamond nagura the cutting speed is exceptional. This is
old stock from the now closed Nakayama mine and I speculate that it was dug
in the 1940s or earlier. There is evidence in the form of adhesive residue of
some sort on the back that the stone was at some point mounted to a base.