I have a 75x200 (8" x 3" to us metrically challenged) natural combo. I bought it about six years ago; long before Ardennes was classifying stones by hardness. While I don't have an extensive coticule collection, I do have one that makes slurry on its own it's so soft. The 8x3 is toward the other end of the spectrum. It's more like glass. A great polisher and a great all around stone when coupled with a slurry stone. Instead of the creamy chalky look and feel of my softer coticules, it looks like this close up:
Attachment 147842
The coticule side is more of an yellow/olive color.
It seems like the larger stones are a bit harder to come by more so than they used to be?
ChrisL