Thread: "Portanigra" What kind of hone is this?

I have found a hone at my fathers place wich I can't find any information about on the internet.
The box says: "Portanigra" all the info I'm getting is about a monument in Germany - Trier.
I have flattened the stone becouse it had a lot of deep scratches from shizzles, and it is very smooth, it feels a lot smoother than my Taidea 8k chinese hone, and if I put a razor on it with no slurry it doesn't even feel abrasive.
Could it be a good step after my 8k Taidea, maybe a nice finisher? Really curious!
Here are some pictures of it:
(EDIT: the vague letters on the box are saying "Portanigra" )

Could be some branded thuringian stone for fine tools and ect. What is the size of that stone
Could be some french hone also rebranded .

Originally Posted by RusenBG

Could be some branded thuringian stone for fine tools and ect. What is the size of that stone
Could be some french hone also rebranded .

The dimensions are:
195(aprox)*45*20mm

So if it could be a thuringian, I can put a razor on it safely?

Originally Posted by Humanalien

So if it could be a thuringian, I can put a razor on it safely?

If it's a thuringian it will make a amazing razor hone. Post a picture with a slurry and that should give some more insight on what it might be!

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Originally Posted by Humanalien

So if it could be a thuringian, I can put a razor on it safely?

Also do you have a picture of it before it was lapped?? If so can you post that too

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I have no picture before lapping, but I have taken one from the backside.
I have tried to hone on it and I must say it really polishes the edge.

Who knows: the Romans may have used hones instead of bricks to build the porta nigra.
There's quite a few hones still available to anyone who fancies extracting a hone:



Looks like a nice hone. The fun part of collecting hones is to find their proper place in your progression.

Originally Posted by Humanalien

I have no picture before lapping, but I have taken one from the backside.
I have tried to hone on it and I must say it really polishes the edge.

Well I can't rule it out of the thuringian category. Hopefully someone who is more familiar with the stone will chime in later.

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Nice hone you got there Humanalien!
It is some kind of slate most probably, but from the structure of the surface shown in your detail pictures it doesn't look like a thuringian.
As said the porta Nigra is a roman building in the town Trier that is located by the river Mosel. Along that river there had been a lot of slate mines in former times, so my peronal suggestion is, that it could be a Mosel slate. Doesn't say anything about the performance though, could well be as good as a thuringian.