Color, polarization and albedo data are summarized for the three known minor planets of optical type E - 44 Nysa, 64 Angelina and 434 Hungaria. The inventory of E asteroids with dimensions > 50 km is shown to be essentially complete. The surfaces of the E objects evidently consist of colorless, translucent, iron-free silicates such as plagioclase, forstefite, or enstatite. Their possible identification as the source of enstatite achondrites is consistent with new laboratory polarimetry of the Norton County aubrite. Both Nysa and Hungaria seem to be rather favorably situated for the production of meteorites. Nysa has a highly non-spherical shape, and is dynamically associated with the metal-rich asteroid 135 Hertha and several small objects also apparently of the metal-depleted E type. The configuration is suggestive of the fragments of a differentiated parent body, in which Hertha originated as the iron core and Nysa as the largest surviving mantle fragment. The relative volumes, however, are not consistent with simple igneous differentiation from a chondritic composition.