Powder patterns of magnetic domains on various crystallographic surfaces of pure and doped hematite single crystals have been studied at room temperature and in the vicinity of the Morin transition. The observations below room temperature were made with an apparatus employing thermoelectric cooling modules. It was concluded that the domains were either slabs or cylinders of irregular transverse cross section with axes lying parallel to the basal plane. The domain walls were determined to be 180° ones. At the Morin transition, a light diffuse colloidal line is formed at the boundary between two phases, one weakly ferromagnetic and the other antiferromagnetic. On warming or cooling, the boundary sweeps across the crystal in a characteristic fashion.