Fun to imagine on geophysical length scales that each dot of gold-sulfur rich complex in the diagram could represent like several orders of magnitude more gold than has ever been mined out of the Earth to date.

(No idea whether that is the right sizing, but I could totally imagine it being the case)

edit:

"...The estimated amount of gold ever mined is around 212,582 tonnes, according to the World Gold Council. This is roughly equivalent to a cube of gold that's about 22 meters on each side..."

https://www.gold.org/goldhub/data/how-much-gold

https://www.usgs.gov/faqs/how-much-gold-has-been-found-world

Referenced paper: https://pnas.org/doi/10.1073/pnas.2404731121

Fred Hoyle theorised (or popularised other peoples theories) that it squeezed like water from the interstitial spaces in the rock under geological time and pressure. I've got a book of his from the 60s discussing planetary formation which mentions it.

I await for this to be incorporated into the Dwarf Fortress world seeding algorithm ;) .

My layperson understanding was that all of the surface gold (i.e. available to humans, not in earth's core) was delivered here via comets/asteroids.

The explanation I received was that the densest atoms (e.g. gold) migrated into the core over billions of years (because: gravity; gold is twice as dense as lead).

For the curious: Around 75% of post industrial gold mined globally comes from deposits linked to volcanic and hydrothermal activity

I’ve never heard a good explanation for why elements like gold appear together in veins. Why aren’t atoms of elements randomly distributed.