David Weaver
..except way different. I remember in my younger days when I was an avid shooter reading about ball vs. disc vs. cylindrical powder, though reloading isn't really a suitable thing for the average person to experiment with.

I gather from this that calcined particles may be finer depending on how microns are measured, and they may be more regular in shape.

For lack of a better way to state what I recall, I remember patrick chase telling me that calcined alumina in autosol would explain its fineness despite its rating. I don't have accurate memory further than that and had assumed maybe it was friable.

For purposes of buffing here, though, I think knowing that the buffed edge can be free of visible scratches, that's the standard I'd apply regardless of what the abrasive is. It's an easy standard to judge.