Thread: ID this stone please

I'd clean it (just by taking it outside and using a plastic bristle brush or something to clean it off) and keep it around. Carborundum stones that are porous and coarse are not preferable for razors, but you may have a razor that has extreme damage that you'd use it for. (not for finishing, though, unless you'd chance into one of the carborundum hones that was specified for razors - those look different and have smaller particles).

They are also fantastic for setting up a new bevel on knives, which tend to be a little softer than razors and cut very quickly on carborundum.

So, useless for razors? That's probably generally true. But not useless for other things.

The only issues with older carborundum stones is that they tend to get harder as they age, and if you get a newer one, they're friable and a little faster cutting. That's not a real big issue when it comes to light use, though.