Thread: Is this a combo coticule?

This was my grandfathers. It is small 4"x2". Is it too much of a pita to use a stone this small as a finishing stone? By the way there is no stone to make a slurry with, but I have read that some people do not use the slurry. Thanks for all of your opinions.

I doubt it, the line between them looks like glue, and as far as I know the belgian blue was never glued to a coticule for mass distribution.

Find an old blade that you can experiment with and see if the blue side sharpens the steel.

There are a couple of people here who have a Belgium combo that is glued, so it is possible that that's what you have! Looking just at the picture though I wouldn't know for sure.
If it is bluish or purplish in color it is likely a Belgium blue, on the other hand, if it is greyish it is not likely a blue but rather a slate backing for the coticule!

Huh, you learn something knew everyday.

Cuticule/Berlgian blues were glued as combo stones up until about 80 years ago, and hen they stopped doing it for some reason.

As for this stone, I'd lap the dark side. If the slurry you get is purple-brownish it's likely a belgian blue. Another thing is that the slate backing you get on modern coticules are generally a uniform dark colour, while belgian blues have a bit of a speckled look.

I've got a blue....and I've got a yellow...and that looks like a blue/yellow combo to me.

That's a blue-yellow glued combo alright. Very nice stone. You'll get used to 4x2. Maybe not ideal for serious elbow-grease honing but for touch-ups and finishing it's a great size.

Glued blue-yellow combos are relatively rare but they exist alright; I have one.

I just picked up a stone on E bay, looks just like your blue stone. I was surprised at how hard it was when I started to lapp it. The Norton lapp stone made very little headway. I thought coticles were soft. Have you lapped yours?
Thanks
Al

It appears the blue side's corners have been rounded.
For a reason, eh.

Coticules are quite hard actually.