The Birth of Gold: A Cosmic Event

Our sun is not hot enough to create elements heavier than iron. All the gold, all the silver, all the iridium of this world therefore comes from cosmic catastrophes: from supernova explosions and from the collision of neutron stars — those unimaginably dense cores left behind by dying giant stars.

In June 2013 astronomers were able to observe such an event: a gamma-ray burst of less than a fifth of a second betrayed the collision of two neutron stars. Researchers estimated that gold of roughly ten times the mass of the moon was created in it. Carl Sagan’s famous sentence holds literally: we are made of star stuff — and our jewellery is matter from colliding stars.

Gold probably arrived on the young Earth with a shower of meteorites almost four billion years ago. It has remained rare: all the gold ever mined in the world would together form a cube of only about twenty metres per side. In mining, a tonne of rock holding a single gram of gold already counts as worth extracting.

Whoever holds a bottle of colloidal gold holds stardust in the literal sense: matter older than the Earth itself, born in the fire of a cosmic collision — now finely dispersed in purest water.