Ok, now I'm that guy. "I bought this hone today, what is it"?[emoji12]
I had extra time in Norfolk today and hit a few Antiques Shops. I was able to negotiate some prices and grabbed a mystery stone for $20.
Now to figure out what I have. I wetted it in the store and could see that it was pretty slick, after wiping the dirt off. I stopped at a hardware store and bought some wet dry sandpaper and lapped it a little with 220 on the hotel granite counter to clean it. It's about 4X8 by over an inch thick. Even if it turns out to be a dud for razors, it might be good for knives.
Any ideas what I have?
Dry after 5 minutes on 220

Wet
Thanks guys.