Iron

Native, or natural, iron is rare in the mineral world, and as such is rarely encountered in gemstones, although it can be fashioned into jewellery, especially iron found in meteorites - by far the most common source.

Iron, or nickel-iron alloys, comprises those meteorites that are metallic in nature. When a nickel-iron meteorite is cut and treated with acid, it can reveal characteristic criss-cross patterns called Widmanstätten patterns, after the discoverer. Jewellery comprising meteorite iron treated in this way is not very uncommon.

Native iron is also found in some igneous rocks on earth, although this is very much rarer.