Thread: Stone Identification

Ok I scrubbed the hell out of it with soap and water (a little cleaner but not much). I then went on to the oven cleaner, not much luck. I did lap it with sand paper from 320 to 1500 grit through 2 drawn grids it is now flat. I do not think the back is a blue I ran a pocket knife over it a few times and it damn sure didn't feel like any sharpening was going on, unlike the other side. I posted a full pick of it as well. So I guess my final question is would anyone take a razor to it? Oh around what year did they start using slate on the back?