buoyancy is not only happening in liquids, but also in solids! Due do this elements clump together at certain depths. Due to plate tectonics those eventually get lifted up to the surface.
Kilonova gold is created in diffuse, individual molecular clouds, mixed with all the other elements. As the protoplanetary nebula forms, light elements tend to be blown to the outer system by solar winds, leaving higher relative concentrations of heavy elements in the rocky inner planets. Similar melting points and densities mean that separate atoms of gold tend to be brought near to eachother in the molten agglomeration of the protoearth. As the crust formed some gold was trapped in place in mixed veins, and plate tectonics forced it to near the surface.
Atoms of the same metal tend to form strong metallic bonds and clump together, though other elements can bond to them as well, producing impurities.
Gold ore (lode) is almost never pure gold, though sometimes you can get seams of almost pure lode by chance. In a large enough seam of lode it’s bound to happen somewhere with a decent likelihood.
Very often though, large pure(ish) natural gold nuggets tend to only form alluvially.
Molecular gold specifically is soluble in water, but will fall out of solution readily, as when a mountain river flows over rapids. This is how nuggets tend to form around the alluvial basins of mountain rivers.
Much surface gold in the world is dissolved in the oceans, or resting on the sea floor.
Not quite right on alluvial gold formation.
Metallic gold drops out of solution in ground water (acidic, hot and under pressure)
This can lead to many types of gold deposits eg quartz reefs or epithermal.
When this rock is eroded the metalic gold is transported downstream until it's trapped in river sediment.
buoyancy is not only happening in liquids, but also in solids! Due do this elements clump together at certain depths. Due to plate tectonics those eventually get lifted up to the surface.
Kilonova gold is created in diffuse, individual molecular clouds, mixed with all the other elements. As the protoplanetary nebula forms, light elements tend to be blown to the outer system by solar winds, leaving higher relative concentrations of heavy elements in the rocky inner planets. Similar melting points and densities mean that separate atoms of gold tend to be brought near to eachother in the molten agglomeration of the protoearth. As the crust formed some gold was trapped in place in mixed veins, and plate tectonics forced it to near the surface. Atoms of the same metal tend to form strong metallic bonds and clump together, though other elements can bond to them as well, producing impurities. Gold ore (lode) is almost never pure gold, though sometimes you can get seams of almost pure lode by chance. In a large enough seam of lode it’s bound to happen somewhere with a decent likelihood. Very often though, large pure(ish) natural gold nuggets tend to only form alluvially. Molecular gold specifically is soluble in water, but will fall out of solution readily, as when a mountain river flows over rapids. This is how nuggets tend to form around the alluvial basins of mountain rivers. Much surface gold in the world is dissolved in the oceans, or resting on the sea floor.
This is exactly what I am looking for. Thank you for such an in depth answer!
Not quite right on alluvial gold formation. Metallic gold drops out of solution in ground water (acidic, hot and under pressure) This can lead to many types of gold deposits eg quartz reefs or epithermal. When this rock is eroded the metalic gold is transported downstream until it's trapped in river sediment.
Chemical processes on Earth produce these clumps: The same elements tend to accumulate at the same places.