Neutronium, an extremely dense matter found in neutron stars, raises questions about its potential as armor due to its purported toughness. However, the stability of neutronium outside of a neutron star is highly questionable, as it requires immense gravitational pressure to remain intact. Without such conditions, neutronium is likely to be unstable and could "explode," making it impractical for use as personal armor. The discussions highlight that while neutronium could theoretically absorb impacts due to its density, the challenges of maintaining its structural integrity in a non-stellar environment render it unsuitable for practical applications. Ultimately, the concept remains largely speculative and rooted in science fiction.