Telluric iron, also called native iron, is iron that originated on Earth, and is found in a metallic form rather than as an ore. Telluric iron is extremely rare, with only one known major deposit in the world, located in Greenland. Introduction With the exception of its molten core, nearly all elemental iron on Earth is found as iron ores. All metallic iron was thought to have been transformed into iron oxides during the Great Oxidation Event, beginning roughly 2 billion years ago, among other theories. Until the late 1800s, iron as a native metal was only a matter of speculation, outside of isolated Greenland. The only known, terrestrial iron in metallic form were found as meteorites, which were deposited onto the Earth from outer space. Telluric iron is so named after the Latin word Tellus, meaning "Earth" (the planet, as opposed to terra meaning "earth": the land, ground or soil), combined with the suffix -ic meaning "of" or "born from", differentiating it from meteorites. Telluric iron resembles meteoric iron, in that it contains both a significant amount of nickel and Widmanstatten structures. However, telluric iron typically contains only around 3% nickel, which is too low for meteorites, of which none have been found with less than 5%. There are two types of telluric iron: Both type 1 and type 2 contain comparable amounts of nickel and other impurities. The main difference between the two is the carbon content, which greatly affects the hardness, workability, and melting point of the metal. Material properties Telluric iron is metallic iron that formed within the Earth's mantle and crust. Although minor deposits of telluric iron have been found around the world, the west shores of Greenland hold the only known major deposits. However, these deposits may vary drastically in shape and composition, even in the same region, as well as drastic variations between different regions such as Uivfaq, Asuk, Blaafjeld, and Mellemfjord. The common factor is that all Greenlandic deposits tend to be found in dikes (lava-filled fractures in the bedrock) or extrusions where molten rock was able to flow out onto the surface. Another commonality is that all deposits are found in association with graphite-rich feldspar, likely contributing to the high carbon-content and low oxide presence in the metal, although it is unknown if the metal managed to escape being oxidized with the rest of Earth's iron, or if it began as