OK, I Might have to revise my opinion of this stone somewhat. Tonight, I used the agate as a burr chaser after a washita stone (this is on tools, I still haven't used it on razors). It is uncanny how slow it's cutting. It brings the back of my chisel to a super bright polish, but it cuts so slowly that if I have any other grooves in the back of the chisel that I couldn't see previously, they present themselves.

With the "already sharp edge" coming off of a washita that is very well settled in (think translucent arkansas for about how sharp this washita makes a chisel), and a LOT of pressure on the chisel edge and back, I get an edge that is sharper than any arkansas stone I've ever used.

That leads me to consider two things:
1) the kind of pressure I used isn't acceptable for a razor, not even a tenth of it.
2) even if I can't use that pressure, it's possible that this could be a good smoothing of the edge following another very fine stone like a chinese stone.

I'll see next time I hone what it does as a follow-up to the razor.

It definitely does not care for steel that's alloyed much. I used a chisel that's not as hard as a razor and that is very plain steel.

I found this out because I was going to toss 1 micron diamonds on it and use it as a strop for tools. Now I won't be doing that, it's got some potential to chase burrs on paring chisels and leave an edge that is rivaled by the best natural edges I've seen.