Thread: Is this a vintage coticule?

Yeah, I concede - not a coticule. Not sure what that is.

Should I try and build slurry on it or use it just as a finisher?

Try it on water only. If you'd like to examine the scratches, it helps if you start with a completely polished piece of metal (doesn't need to be a razor). Maybe a knife, or a piece of steel, a steel bar.... if you are able to polish it, like using W&D paper up to 2500, then chrome oxide to remove those 2500 scratches, that should be good enough.

I'd just try it on a knife personally, and see where it gets me. Razors only if it fine enough and doesn't chip a knifes edge. Or if you have a beater razor, something you don't care about, then just grind away....

I did put kitchen knives on it before any razor with very good finishing results as it is a very low grit stone, before getting this hone I used lapping films (5m, 3m, 1m) for honing my razors and I was getting very sharp edges, by putting razors on this stone after the 3m lapping film I got really sweet edge and very smooth shaves, I would say that it gives a more mellow edge than the 1m lapping film.
Another thing to mention is that it is very hard and took me hours to lap it flat with W&D paper from P280 to P800, I wonder if I could use it with a slurry stone but having no idea of it's kind I don't know what stone to try for building slurry on it.

A hard Arkansas hone works will as a slurry stone. Small ones for knives are very cheap. They will work like a diamond plate to produce slurry from the larger hone.

Thank you very much I'll try it as I do have a small translucent Arkansas stone.

looks a bit like an arkansas stone.