not sure, what ya think.

[berti]

 

[monsterrack]

I don't see any deliberate flaking, looks water worn. good eye HH

 

[GatorBoy]

I would have picked it up..
Just by the photos here and a close look I think its natural.

 

[unclemac]

I don't see any deliberate flaking, looks water worn. good eye HH

...but is sure is pretending to be something, trying real hard too.

 

[NC field hunter]

Perhaps a preform? I think I would hold it until a knowledgable person is able to study it in hand. If this is nature, it's a good fooling she laid on you. Or, most of us, had we found it.