However, because they formed volatile hydrides on the primitive Earth when the controlling redox reaction was the oxidation or reduction of hydrogen, the less metallic chalcophile elements are strongly depleted on Earth as a whole relative to cosmic abundances.
12.
However, given Ir's low cosmic abundance, several orders of magnitude below V, Fe, and Cu ( which are actually used by terrestrial organisms ) and Mn and Co ( which would also work, but AFAIK are unattested in terrestrial organisms ), it seems rather unlikely that this compound is used in any alien species'blood . talk ) 03 : 18, 11 December 2014 ( UTC)
