I went to my barber the other day to get my unruley mop trimmed & noticed a box of stones--one of which I just finished lapping (after agreeing to bring it back next week). It's ~8.5x1.5 & super fine. Greyish-blue color. Took 5-10 min on my D8C. There's also another one ~4x1.5 that has a speck or reddish paper w/ black lettering on it. I'm almost positive that's an Escher. How about the bigger one? (Hone/shave test coming up!!!)
I'll post pics in a bit.