How is gold created out of the collision of stars composed of neutrons?
Relieve that pressure -- by flinging bits into space in a collision or explosion -- and it reverts to neutrons + protons + electrons + antineutrinos, forming first ultramassive nuclei, which rapidly decay to stable elements, many being heavy elements well above iron in atomic number.
The nuclei mar be formed by r-capture (rapid capture), or perhaps devolve from dense neutronium clumps.
They are composed predominantly out of neutrons. Some percentage of their composition is still electrons and assorted atomic nuclei, which is a non-trivial amount of matter considering the common range of density they tend to have.
I would imagine all kinds of interesting(strange?) interactions take place when such dense and energetic objects collide.
This raises the question of why gold tends to be found near other gold on Earth.
Like attracts?
[0] https://www.quora.com/Why-is-gold-frequently-located-in-quar...
When you spin a combination of stuff that is "loose enough" at sufficient speeds, the centrifugal force acts on the constituent masses differently. As a result similar masses coalesce.
This is the same principle used to separate and concentrate (enrich) all kinds of stuff in centrifuges.
Gold at earth's surface tends to be found in deposits where water with gold particles in it was flowing through a crack for an extended period of time.
Over time some of the gold is deposited on the sides of the crack, essentially concentrating it through evaporation and deposition.
These cracks then become what miners call 'veins'. Other metals and minerals have similar stories.
TLDR: water from deep in the earth carries gold particles upward. Cracks form consistent flows which concentrate deposits over time.
I didn't know that fact about U, thanks.
This is why mining asteroids for siderophiles (like gold, but also platinum group elements) has been a staple of space advocacy.