the transformation to pyrite yielded the highest conversion rates also show that intentional oxidation drove
the reaction at a much faster rate while unoxidized samples remained stable. Such surface oxidation may
also explain why pyrite is observed in experiments under presumably anoxic conditions.also noted that at 160 C, the conversion of monosulfide to pyrite in anoxic experiments, proceeded much faster than below 100 C, possibly indicating an upper limit of the thermal stability of mackinawite. In a forthcoming paper, however, recent experiments have
shown that mackinawite might persist to at least 180 C