Derain is a crater on Mercury. It has uncommonly dark material within and surrounding the crater. The material is darker than the neighboring terrain such that this crater is easily identified even in a distant global image of Mercury. The dark halo may be material with a mineralogical composition different from the majority of Mercury’s visible surface. Craters with similar dark material on or near their rims were seen on the floor of the Caloris basin during MESSENGER’s first flyby.