As some of you know, nuclear pasta is the hardest substance in the universe found in the innermost crust of neutron stars with a density of ~10^17 kg/m^3.

So in the book I'm writing there's this character with a katana composed of this stuff. The weight of the sword would probably be a bit impractical, but I suppose that can be counteracted with magic.

But what other effects can be expected from nuclear pasta in Earth's atmosphere? Is it stable? Is it radioactive? What other contingency magics will have to be introduced to make such a blade reasonable?