☞ Meteorites usually show a pitted surface with a fused crust, caused by the heat developed in their rapid passage through the earth’s atmosphere. A meteorite may consist: . Of metallic iron, alloyed with a small percentage of nickel (meteoric iron, holosiderite). When etched this usually exhibits peculiar crystalline figures, called Widmanstätten figures. . Of a cellular mass of iron with imbedded silicates (mesosiderite or siderolite). . Of a stony mass of silicates with little iron (meteoric stone, sporadosiderite). . Of a mass without iron (asiderite).