In this talk I will summarize recent breakthroughs made in the development of iron sulfide, or Fool’s Gold, as a low-cost, earth-abundant, non-toxic photovoltaic material, that have created new pathways toward sustainable solar cells. We have made significant strides in understanding the doping in this semiconductor as well as its unique surface conduction properties, both of which being key to uncovering the reasons for poor FeS2 cell efficiencies despite being an ideal material on paper.