Naniwa diamond stones: 6k and 8k ($200)

[jeffus]

Naniwa Diamond stones, 6k and 8k. $200

I don't think these are really for razors. I tried various mediums, but the edge tends to get nicked. However, under running water the edge did not nick.

I also have not tried these with extra hard steel.

I have used the 6K with kitchen knives, and that's rather fun.

The 8K doesn't seem to be available anymore, at least with a simple google search.