Slurry is one of the telltale signs.
On a razor that is 61 HRc, if you hone on a 1K or 4K, the metal will take a long time to abrade.
So it will take some time for the slurry to turn from clear water to grey.
Otoh, if a blade is say 50 HRc, the same will happen much faster, because it abrades faster.

And of course, a blade that is 50 HRc will not be able to hold a shaveready edge for any significant amount of time, if you can get there at all.