Originally Posted by
TransWorld
That is contrary to what Glenn Seaborg told me, face to face. For Pu-238, there is no naturally occurring. I respect you, Rick, but I respected Glenn on this topic, even more.
You can google it. Technically, EVERYTHING in that general range on the table can occur naturally (possibly very, very rarely but it happens).
https://www.scientificamerican.com/a...t%20it%20there.
As I said, for practical quantities, it has to be man made. It occurs very rarely, and has such a short half-life that you just can't access any appreciable quantities in nature.