Thread: A lucky stone

HAD is a dangerous thing, you realize that when you start buying random stones from eBay, with no proof of quality and origin.
I have a case of the JHAD which a few weeks ago led me to bidding on a unknown JNAT stone.The description was that its a finishing stone and that was enough for me to jump on it. I won it and received the package 2 days ago. The pics on the auction do not do jutice to the stone (neither do mine but they are at least better).
The stone is very smooth to the touch, there was some Kanji on it that I did not bother taking pics of, it is gone now that the stone is lapped.

I put a razor on the stone and felt like the scratch pattern was very fine, so good sign there. I had to work on a razor today, I used a 3k chosera , then I went to the stone with heavy slurry for some time not counting laps just working by feel. After I finished honing, which took ~5 min from 3k to finish, I stropped and tested , the edge was surprisingly smooth, but just a tiny tad lacking. I ran the razor on the CrO and CeO strops and got a super smooth shave.

The stone turned out to be a great finisher, I was able to get great edge just by doing very general honing with no regard to lap count or slurry thickness. After a few tests I am sure I'll nail the right method for the stone, but getting a great shave with the first razor to touch the stone is a great sign IMO.
I guess sometimes one can get lucky on the eBay, for little money.

Now some eye candy, as I said the pics do not do justice, when wet the stone has gray, pink, purple and yellow/orange colored parts on the surface, very beautiful. I wish I knew what mine it comes from

I'm sure it isn't but it looks very much like sandstone or its metamorphosed brother quartzite.

Originally Posted by thebigspendur

I'm sure it isn't but it looks very much like sandstone or its metamorphosed brother quartzite.

when I opened the package and saw the dark yellow and orange, I thought "
Man that looks like one of my Jnat bevel setters, what a waste" but surprise surprise, cool looks and ability in one package for just under 90 bucks it can't get any better.

Congrats on a great score, Stefan!

The white/pink areas look like chert (microcrystalline quartz) that is interbedded with the clays. If so, you may see a difference in the ability to raise a slurry across the surface (possibly less on the chert).

looks nice stone. Congratulations.

Originally Posted by Woodash

The white/pink areas look like chert (microcrystalline quartz) that is interbedded with the clays. If so, you may see a difference in the ability to raise a slurry across the surface (possibly less on the chert).

if that means less binder and more abrasive then that is all good.
I have a Nakayama that is mostly abrasive with little binder and karasu, its the fastest cutter and also the hardest stone I have seen. Pretty hard to raise slurry too.

Originally Posted by mainaman

if that means less binder and more abrasive then that is all good.
I have a Nakayama that is mostly abrasive with little binder and karasu, its the fastest cutter and also the hardest stone I have seen. Pretty hard to raise slurry too.

Yes, I would expect the cherty areas to be more abrasive as well. Any slurry from the chert would probably not break down much to finer size fractions as you hone. That Jnat 'slurry effect' may be coming more from the clays. If that’s the case, then a cherty stone would conceivably be a more aggressive cutter, but not necessarily as good a polisher. Just speculating....