Petrographic, SEM, and STEM images of bladed marcasite and bladed pyrrhotite

Petrographic (A, D) SEM (B, E) and STEM (C, F) images of bladed marcasite (A, B,C) and bladed pyrrhotite (D,E,F). The petrographic images are reflected light under plane polarization. The brassy minerals in D are isocubanite being replaced by chalcopyrite. From the study Spontaneous combustion of metal sulfide minerals and implications for seafloor massive sulfide mining.