question 1 | If all the heavy elements are formed in stars, picked up by the accretion disk, and from there find their way into planets -- why do we find seams of gold, iron, tin and so on? Shouldn't it all be mixed up? Or have the past few billion years been a case of constant subtle perculation and distillation, tiny statistical differences having huge effects over geological time, moving all like materials to the same places? Answers.