It's the same when you try any "Natural" stone, you have to play with it.

First thing I do it to determin if it is flat, flatten if needed.

Once I have it ready to hone with I'll hone a razor to the point where I need the "new" hone. If it's replacing a stone I'll use the new one to see how it shaves, than go back a stone to "rough" it up a hair and finish on the replaced hone to see the feel.

Here is where it gets dicey, as you still have to see what the new stone likes. Naturals are just like that and you have to play with them to find that sweet spot.