I have been looking around a bit lately for a natural finishing stone to use primarily on my japanese blades (planes and chisels). After reading a recent article by Toshio Odate in a magazine on his sharpening techniques I saw where he mentioned a Belgian Blue Stone. After searching a bit I came across the site The Perfect Edge which carries some stones out of a Belgian Quarry. But the blues do not seem fine enough and went on to read about the Yellow Coticule stones. Just curious if anyone around here has any experience with any of the stones out of that quarry and what kind of characteristics they have.

Some other natural waterstone suggestions would also be very welcome, mostly some finishing/polishing stones that I'd be interested in. The natural waterstone market is loaded with different stones that just boggles my mind and really is a tough place to get started in. With the price of some of these good quality stones I struggle with the notion that the stone I end up picking will not be what I am after. Any literature online on natural stones would also be a huge help.