I really enjoyed the abstractions in this piece, particularly this:<p><i>Iron from the mantle, released at black smokers, has a predictable ratio of iron-56 (full fat) to iron-54 (lite), but in the Hamersley rocks the ratio is skewed; the iron is, on average, lower-fat than expected.</i><p>It made for enjoyable reading what was essentially a piece describing why most of the mined iron deposits we use to make steel have a certain isotope - single celled organisms de-oxygenating rust molecules and expelling iron-54 as a waste product.