Can anyone identify this stone...and is it usable?

Found it laying around the house. Looks pretty rough. I did read a post saying how to clean up old stones but I’m not really sure if this is any good or if it could be fixed, heh. Thanks!

its a grey one, case closed 0:)

Looks like my Aluminum Oxide Sharpening stone.

Is that a 2 sided stone - one side is rougher (for grinding) and the other smoother (for finishing)? Looks to have been used - a LOT.

It’s a sharpening stone for honing chisels etc. I wouldn’t use it for that purpose in its current state, but if you need a doorstop…

Yes it is and yes it has.
Could probably use it if it was flattened out but why not use sandpaper?

you can use it to throw at person you dislike, or to break something, say eggs, glass, etc.

Those stones are about useless for sharpening any good knife.

Stones seem to wear down after many “sharpenings”. Yes they did makes my knives sharp. :8)

It’s just a cheap carborundum stone. You can flatten it on a concrete curb or a concrete paving slab. Don’t expect it to be great though as the pictures suggest it’s a soft stone for reshaping a chisels bevel and putting a basic working edge on them.
for cleaning help read through this as it will work no matter how gummed up the stone is,
http://norsewoodsmith.com/content/cleaning-old-oil-stone

The people in this forum are unbelievably helpful. Yes, that looks like an overused sharpening stone. Still usable for old scissors or kitchen knives, i think.

Boil it in water for at least 30 minutes maybe an hour to try and get most of the residual oil off of the stone. Then use some 250 grit paper with the help of a level surface and a piece of straight wood, to level the sides much better. Find out which side is the “fine” or “finishing” side and hit it with some 500 grit or there abouts, sand paper. Go over the entire thing with some steel wool to finish off the cleaning. You can use water or oil to sharpen. Oil it up and let the oil sit on there for at least 30 minutes before usage. I’ve found some of the best sharpening stones are ones that are old, abandoned, found and free. Good luck!

Should work good for sharpening axes, machetes, and the like...