Well no chips falling off. It looks like it was chipped from hitting something. I do know that slate comes in many colors...I guess I didn't say that right. It's not the color so much that makes me think it's not slate. It's that it doesn't seem like it's layered.
I'm going to take the diamond wheel to the top of it then lap it on SIC and see what I get. I just wanted to post some pictures before it was cut to see if anybody had an idea.