I believe that whether the particles break down or don't break down is not settled science.
There's allgedly a paper in Japanese that advances the premise that the grit is all the same and only the hardness varies. I have not seen the paper or a translation, but I can understand that, maybe it's why the finish on novaculites seem to affect the tesults as much as users report.
Bit Todd Simpson at "Science of Sharp" has SEM photos of Jnat slurry showing it doesn't break down:
https://scienceofsharp.wordpress.com...ry-break-down/
So if Jnat particles are all the same and slurry doesn't break down, then all Jnat hones are the same. We all know that isn't true in a practical sense.
But all it means is that we don't yet fully understand what's going on.
Cheers, Steve