Electron microscopy study of CVT grown Fe-sulphides

► Pyrite and pyrrhotite were grown simultaneously by CVT. ► Cubic rock-salt type ccp sequences are prevailing in the pyrrhotite structure. ► Twinning in pyrite is preserved across the interface between natural and synthetic pyrite. ► Stacking faults found in the natural crystal are discontinued in synthetic pyrite. ► With controlling the temperature gradient we can modulate morphology and type of sulphide grown by CVT method.