Search:

"Rare" is a relative word.

For someone its rare for someone its not.
I do not think that the Tsushima sea stone is rare. It can be found it on web for sale in Japan.
On the other side I think...

Not all Tsushima hones are from the sea.
There have been 2 mines in Tsushima.
They are called 山砥 (hone from mountain) and 海砥 (hone from sea).
The hone from mountain is harder and need no...