Definitely interesting.
Too bad it's not available for other shots.
I don't see any chunks of mineral in it. Is there? It looks like clay. The outer rind is darker like it was baked in a kiln.
Is it perfectly round outside? It was already in three pieces when found? How tightly do the pieces fit together? Is there a difference between the material the inner ball is made from and the material of the outer one?
From what I can see in the pictures it doesn't look like it was made by mother nature.