[Jonty30]

Got my answer. It is iron.

Anything above iron is the result of a super nova.

[tlb]

Then again, nevermind :)

[cripplecreek]

I was reading that the first molecule of an element denser than iron at a star’s core means almost immediate destruction of the star.

As I understood it, it creates some sort of back pressure and shock wave that helps create more heavy elements. (as well as the destruction of the star)