What would happen if I break a magnet to an atomic scale?

Let’s suppose I have a pure iron magnet and every atom of that magnet is magnetizated.This magnet has 2 poles(N and S) and if I start to break it I’ll obtain two smaller magnets and both have 2 newly formed poles.All of this is know,that poles are so far inseparable.
What if continue to break the magnet until I remain with only one atom of that magnet.How will that atom be?Will it still have 2 poles?
And what exactly creates magnetic fields(what makes the iron from this problem a magnet)?Why is iron so special that only it and it’s compounds can be magnets?