Earth Science Stack Exchange is a question and answer site for those interested in the geology, meteorology, oceanography, and environmental sciences. It only takes a minute to sign up.
Sign up to join this community
Apparently according to the Parkes Process silver is 3000 times more soluble in zinc than in lead. So why is it that most silver is obtained from galena?
Edit: “ Silver mainly occurs as a contaminant in chalcopyrite and galena, important ores of copper and lead, respectively.” Silver mining
This Wikipedia page cites a few sources as well. So maybe it isn’t most, but a great deal of it is found in galena.
Also the page for galena mentions that it’s an important source of silver.
This may not be a complete answer, but a big misconception here may be that silver is found "in" lead. It would be more correct to say that silver is more concentrated in the lead ore mineral galena, which is different than metallic lead. The solubility of silver in zinc or lead likely refers to the properties of silver-zinc and silver-lead alloys, whereas most natural occurrences are in sulphide minerals (galena for lead; sphalerite for zinc).
This realization makes it more reasonable that silver (as Ag+) would be found preferentially in galena, whose structure can accommodate the relatively large Pb2+ ion, as opposed to the smaller (Zn,Fe)2+ site in sphalerite. In fact, the two metals (lead and zinc) occur together very frequently in economically important deposit types like seafloor volcanogenic massive sulphide and carbonate-hosted lead-zinc (aka MVT) deposits. This may even be compatible with the metallogenic association between silver and zinc you imply by their higher miscibility; it's just that silver is less easily incorporated into the zinc sulphide lattice than that of its common partner lead.
