Campo del Cielo iron meteorite slice, etched and polished on both faces to reveal a handsome Widmanstätten pattern. The full slice weighs 242.1 grams and measures approximately 151 mm x 98 mm x 4 mm. One side has a few fingerprints to the finish. The Campo del Cielo meteorite is believed to have fallen to Earth 5,600 years ago and was first discovered in Argentina in 1576; it is one of the oldest known meteorites on Earth. Accompanied by a certificate of authenticity from Aerolite Meteorites.
The interiors of some iron meteorites tell a story that is markedly different from their exteriors, and this hefty Campo del Cielo lab-prepared section is such an example. The structure of iron meteorites is determined by the examination of two nickel-iron alloys—taenite and kamacite. As a result of very slow cooling in space, these alloys typically form into a complex interlocking crystalline motif known as the Widmanstätten Pattern, named after Count Alois von Beckh Widmanstätten who recorded the phenomenon while experimenting with iron meteorites during the 19th century. This miraculous lattice-like arrangement can be very beautiful and is generally visible only after iron meteorites have been carefully prepared in the laboratory by cutting and polishing, followed by etching of the cut surfaces with a volatile solution of alcohol and nitric acid, known as nitol. The kamacite crystals revealed by this process are measured and the average bandwidth is used to subdivide iron meteorites into a number of structural classes. An iron with very narrow bands, less than 1mm, is known as a 'fine octahedrite,' while one with a very wide band would be described as a 'coarse octahedrite.' Campo del Cielo is a coarse octahedrite and its silvery interlocking bands, known as lamellae, can very clearly be seen in this example.
