I brought my Red Oohira stone from last JNS gathering in November. There is toxic line or inclusion which goes through half length of the stone and almost through whole deepness of ite. It splits it in half. Of course you can cut this stone and make tomo nagura's, small traveling size stones or fingerstones, but I wanted to save it.
I have postponed that project for a while, but now I found some time to remove it. I have never removed toxic line before so this is more like a experiment.
Let's start from ''the toxic line'' or ''inclusion''. What is that? The quote below comes from Easternsmooth.com blog:
''There are two basic types of inclusions: lines (called Suji?) and specks, called "hari" or "ishi" or sometimes "Suna-me" or sand eyes. Basically, these are accretions of minerals that are harder or of a different coarseness from the rest of the stone. If they are in areas that can hit your edge, they are called "living" and are best avoided if possible. If they don't hit the blade, they are called "dead" and, of course, aren't a problem. Both cases, however, can cause a drop in the price of the stone.''
So here it is. My Red Oohira:
So here you can see my line going through the whole depth of my stone.
Let's look at it in the 60x magnification. Please note that I took those pictures with phone camera and some kind of magnifier so colours might be little bit different.
So my today's tool of choice was my girlfriend's manicure set...
Of course I have rounded the sided as well.
It was time to test it. I used my Suisin Densyo White#1 270mm yanagiba. This is how it looks before:
And after Red Oohira.
This is Red aoto finished blade with uniform scratch pattern:
Short movie. Unfortunately memory in my phone was gone seconds before end of the movie:
That's it. Now I know that toxic line are not that scary and I have a great stone . Thanks for watching and take care...