Five percent of the earths crust is made up of Iron. Native Iron is rare in the crust, and is invariably alloyed with Nickel. Low nickel iron up to 7.5% nickel is called Kamacite, and high nickel iron up to 50% nickel is called taenite. Both of these froms of nickel are mainly crystalline in the cubic system. A third form of Iron-nickel that's mainly found in meteorites, and crystalizing in the tetragonal system, is called Tetrataenite. All three forms are generally found either as disseminated grains or as rounded masses. Kamacite is the major component of most iron meteorites. It is found in most chondriiic meteorites, and occurs as microscopic grains in some lunar rocks. Taenite and tetrataenite are mainly found in meteorites, and often intergrown with Kamacite. Iron is also plentiful in the sun, and other starts in our galaxy.