The main difference between the two is the carbon content, which greatly affects the hardness, workability, and melting point of the metal.

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 beds of ore and coal that subducted and then were naturally smelted in the lava due to the reducing environment provided by the carbon-rich, graphitic feldspar.

Telluric iron in Greenland is unique, in that it can be found in nearly all phases of iron-carbon alloys, and with drastically varying crystalline structures.

Still in others the dike or extrusion may be made almost entirely out of very high-carbon cast-iron, which could more easily coalesce within the magma and flow into cracks due to its lower viscosity and melting point.

The metal could not be cold worked by the ancient Inuit, (the local inhabitants of Greenland), and proves extremely difficult to machine even with modern tools.

When sawed in half, boulders of type 1 tend to have a thick shell of cast-iron on the outside that can barely be broken with pneumatic jackhammers, but inside a much more brittle construction of iron grains in an almost powdery form, sintered together to form a porous, sponge-iron type of material that pulverizes at the strike of a hammer.

The material was found in the volcanic plains of basalt rock, and used by the local Inuit to make cutting edges for tools like knives and ulus.

Knowing that the Inuit had made tools from the Cape York meteorite, mainly due to Sir John Ross' discovery that the natives of Greenland used iron knives, Nordenskiöld landed at Fortune Bay on Disko Island to search for the material.

One was very hard and could not be broken, but the other was chipped into smaller pieces from which balls of iron were extracted and hammered into flat discs for the knives.

Nordenskiöld searched unsuccessfully for the site, until being led by some of the local Inuit to a place called Uivfaq, where large masses of metallic iron were strewn about the area.

Armed with dynamite and lifting equipment, his expedition collected three large samples of telluric iron, also believing them to be meteoric, per Nordenskiöld's examination, and brought them back to Europe for further study.

Since the type 2 grains are embedded within volcanic basalt that matches the underlying bedrock, Steenstrup was able to show that the iron was from terrestrial, or telluric, sources.

... Metallic nickel-iron with Widmannstätten figures has now been proved to be also a telluric mineral, and the presence of nickel together with a certain crystalline structure are consequently not sufficient to give the character of meteorites to loose iron blocks.

[5][6][7] In addition to the Disko Island deposit native iron has been reported from Fortune Bay, Mellemfjord, Asuk, and other locations along Greenland's west coast.