Thread: the correlation between stone's surface polishing degree and the honing it offers

Your stone may have been lapped to 1k grit by the seller but he could have rushed it. It's also possible dirt from the box got on the stone's surface. Some of those UK stone boxes are awefully dirty. 15k seems a bit excessive but kudos for trying

I agree that hard stones seem to benefit from a finer finish. Instead of fine sandpaper or lapping film you can also finish by rubbing it against another hone. I recently did this with a suspected Llyn Idwal and a 1k waterstone, it worked quite nicely.