Figure Above: A 30 nm x 30 nm STM image of a clean Fe3O4 selvedge recorded at Vsurf= -1.52V, I=0.53nA shows a hexagonal pattern of bright protrusions with a ~ 6 Å periodicity. A surface unit cell of the 2x2 structure is marked by the black arrow (upper right). The dark areas, identified by white arrows, appear bright and well resolved, when a positive bias voltage is applied.