Woodcraft polishing stones

[AAvK]

I saw this Chinese natural quarried polishing water stone

final honing of chisels and plane blades. They say they are

12,000 (twelve thousand!) grit for a price that is far lower than any other stone in this grit range, I think this is a great deal but has anyone tried one? Does anyone think the grit rating is a tad unrealistic, or straight up?

[J]

I thought I read Dingley stating that these are only good for grinding ink.

Personally I see no need to go further than say 8000.

-j

[Gordon Airporte]

Isn't the danger with natural stones that they sometimes have irregular particles? Not that an 8000x nick in a 12000x polish would be the end of the world. To be worth it in theory it would have be finer than .5 micron honing compound, which as far as I know is currently the final word in honing. Still, you're splitting hairs at this point ;-).