> From: Coos Haak    
   > Fe++ and Fe+++ are the only stable forms of iron in aqueous solution.   
   > Iron metal is definitily not.   
      
   I'm confused. I was under the impression that banded iron deposits,   
   dated from the time when the Earth's ocean first changed from anoxic to   
   oxic condition, due to cyanobacteria venting oxygen from photosynthes   
   into the ocean, were precipated iron oxide. The neutral iron was   
   previously dissolved nicely in the anoxic water, but the iron oxide   
   isn't as soluble as neutral iron was so much of the iron oxide had to   
   precipate out. Am I mistaken??   
      
   > See above, and your high school chemistry book.   
      
   That book belonged to the school district so couldn't be kept by me.   
   But in any case, that book assumed there's an atmosphere of 20% free   
   oxygen (O2) around any water, with lots of the oxygen dissolved in all   
   samples of water, that oxygen reacting with any neutral iron to yield   
   iron oxide just as it did when cyanobacteria first released lots of O2   
   into the water. So I wouldn't trust that book to say the right thing   
   about what's stable or not in a reducing atmosphere with virtually no   
   O2 whatsoever.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)