Neutronium is only found during the final stage of a star. The star is basicly a corpse after the supernova. And you get left with an ultra dense neutronic material. Simply known as neutronium. And then there are free neutrons. Which are released during nuclear reactions. Neutronium is so dense. That a spoon full of it would weigh in the hundreds of millions of tons...Imagine dropping that from space...Yikes! #3d #NeutronStar #Neutrons #Neutronium #Nuclear #SuperNova #UltraDense