The Formation of Meteoritic Iron Oxide

Meteoritic iron oxide occurs in three forms: coarsely lamellar, finely lamellar, and massive. The lamellar forms result from oxidation proceeding parallel to the surface of the metal. The thickness of the lamellae may be proportional to the rate of oxidation. Massive oxide results when electrolysis causes the oxide to invade the metal or when redeposition of dissolved oxide obliterates the original lamellar structure. The action of lawrencite produces a friable, porous type of oxide which is confined largely to specimens in collections. The effect of electrolysis on the differential oxidation of meteoritic minerals is briefly discussed. Three new analyses of meteoritic oxides (by F. G. Hawley) are given (Table 1).