Gold is not only a rare and precious metal here on our planet Earth, but it is also rare in the universe. This is because the event that occurs when Gold is formed -- rarely happens. Gold was formed about a few hundred million years after the Big Bang. Earth did not receive gold until 200 millions years after the formation of the plant, when meteors with gold smashed into the surface.
A neutron star is the collapsed core of a star (usually weighing between 10-29 solar masses). They have a mass of 1.4 times our sun and neutron stars are the most dense stars in the universe. (They are also the smallest stars known to exist.) A neutron star is so dense that a teaspoon of a star would come out to be a billion tons.
Neutron stars form from the deaths of red super giants. A red super giant is an aging star that has consumed its core supply of helium. This makes hydrogen in the outer shell undergo nuclear fusion.