This is a friends find, it came from Indiana. It is black in color with a red circle, and is a little bit smaller than a baseball, and the stone changes temperature, the surface is very smooth with no tool marks.
No, it's not cupped, it perfectlly round on the bottom, and the top slopes up to a rounded point and the red band in below the point. The red band goes completelly around it. thanks
Interesting,Ive never seen anything like it,There are alot of guys here who know alot more than me, so hopefully someone will know, anyways its a neat peice wahteaver it may be.