Up until the discovery of pulsars it was thought that no atomic nucleus can survive the gravitational forces at the core of collapsed stars. It was thought that the remnants of those collapsed cores consist of some electrons, some protons but predominantly neutrons (thus the name neutron stars). However the discovery of radio waves in pulsars means that neutron stars contain rotating iron cores! This means that the iron survived! Today we know that iron has the strongest bound nucleus among all elements.
[Quran 57.25] ... and We sent down Iron, in it great might...
Iron and most of the elements on Earth came from outer space. Iron was known and used long before the Quran however it was not the best choice for weapons because it rusted and it easily bent. The miracle is that the Quran said "in it great might" at a time when they only knew that it rusted and bent. Today we know that iron has the strongest bound nucleus among all elements. Learn more.
(In the Christian Bible God promised to make the descendents of Abraham as numerous as the stars in the sky and sand on the seashore Genesis 22:17. But our observable universe (the one we can detect with today's instruments) turned out to consist roughly of 100 billion galaxies with each galaxy consisting of about 100 billion stars. This means that the number of observable stars is equal to 100bln x 100bln (that's one with 22 zeroes next to it). So how could God keep his promise in the Bible? How could He make Abraham's descendents 1022? If they breed 20,000 descendent/second and never die they need 13.7 bln years to reach this number. And still they won't fit Earth).