OK well that definitely isn't Karasu. Heres a silly question, have you lapped the hone? Perhaps try it again.
Thanks for the pics, that looks interesting eh. I would love to get a microscope to examine my hones and blades, but just can't justify the expenditure.
Can you send me a pic. Will be interesting just to look at. Not so sure it would be the bad Karasu, So should be able to tell the difference. Also unless you paid an arm and a leg for it, I doubt it to be Karasu.
P.S Depending on the size of the spots, that hone may have been very close to a Karasu strata. Thats a good thing, coz Karasu is rare and damn expensive.
Now were getting somewhere. You want a better edge than that from a 30k Shapton!? I don't think your going to get that from an Asagi. They happily replace 16k's not so much the 30k. The black spots, shouldn't be harmful, they usually help the hone cut faster.
In response to your message, it is almost impossible to tell you anything just by looking at the photo's, I would have to examine the hone in person. Unfortunately with that, the shipping fees to me, would be significantly high I think. I was actually going to tell you yesterday, to go straight from hone to strop, without that news paper thing. It sounds like a **** poor hone from your explanation and I have to ask... Did you make sure you were buying a hone for finishing razors? If there's anything I can do to help, let me know, but first, it might be best you talk with So and see if you can work out a solution.