Dave Burnard
>Chisel sharpening? These days I use my man made middle and finish stones, unless I'm sharpening a paring chisel for the absolute best edge I can make. If I'm going to whack the chisel with a hammer I haven't seen that which stones I use makes much practical difference.

I like to think back to the first US Kezurou Kai (thin shaving contest) which was won by a professional japanese carpenter living in Northern California. He was using a modest plane, and for sharpening he used a 1000 grit King stone and a 6000 grit King S-3. He has much nicer stones but didn't want to travel with them. That's about the most basic stone set you can have, but he was able to get some pretty amazing results from those stones. Once again developing the skills is more important than having the best tools. Rats! ;)

Natural stones are a slippery slope, and an enjoyable one. It's very interesting to see how different irons and steels react to different stones. You'll get a lot of insight into what a sword polisher actually does to enhance or modify the appearance of the hamon on a sword. Unfortunately there are so many varieties, good for different tasks or tools, etc. Can't possibly own, let alone use, everything.

Similar variation exists between man-made stones. If you line up the 20 or so 8000 grit man made stones the differences are surprising. Hard, soft, fast, slow etc.