Thoughts, Opinions, Suggestions...

[SurfaceHunter]

I don't think slate is rough enough to sharpen at least not the type we have it's a smooth texture even in the wild. So in hand is it smooth or rough?

[paohrocks]

Smooth on both surfaces as well as the sides.

[SurfaceHunter]

Sharpening stone needs to be grainy not slick and made from a hard stone.

[BoilerMike]

Looks like a whetstone or fish hook sharpener. I don’t think being smooth rules that out - flat ceramic surfaces and even leather strips are used for fine-honing blades. Maybe it was part of a set with a coarser counterpart at one time? The way I was taught to use one to sharpen a blade wouldn’t dig grooves like that. Maybe if the blade was chunked up from rocks or bone, and the stone was too fine to get the imperfections out without spending hours, then someone might saw vertically to make a straight edge before honing? But what doesn’t make sense to me about that is why are they so evenly spaced? You’d probably start in the middle, then when the groove got too deep to where you need another groove, you’d start another one halfway between middle and edge.

The fishhook sharpener for trebles makes sense as a design, but I don’t think it was used that way or the insides of the grooves closest to each other would be a shallower angle than the outside - and the device would only be useful for a single sized treble, while most fishermen carry assorted sizes. I’m wondering if some fishing tackle artisan a hundred years or more ago made these by hand for that purpose, but the owner used it for single hooks?

Is one end curved? Looks that way in the pic - perhaps there’s a reason for that but I’m at a loss.

Only other thought - perhaps it’s the foot for a piece of furniture, a lamp, or some religious artifact? The leg or base of something might have a pair of ridges that nest into the foot, and the squared end would go against a wall or something with the rounded end pointing out?

[NJ]

I found this abrading sandstone last season. The interesting part of yours is that it seems very decorative for a tool. Awesome piece!