Campo del Cielo Meteorite: The Complete Guide to Argentina's Iron

Campo del Cielo— “Field of the Sky” — is one of the most famous and affordable iron meteorites in the world. It fell across northern Argentina over 4,000 years ago, and so much of it has been recovered that a genuine piece of this ancient iron is within almost anyone’s reach. Here’s the full story, how it compares to the finer irons used in jewelry, and how to care for a specimen.

What is the Campo del Cielo meteorite?

Campo del Cielo is an iron meteorite, classified as a coarse octahedrite — composed mainly of iron-nickel. It’s one of the heaviest meteorite finds on Earth: multiple masses weighing many tonnes have been excavated from its craters. That abundance makes it the go-to choice for a first genuine meteorite. For the wider family, see types of meteorites.

The fall: Argentina, 4,000+ years ago

Around 4,000–6,000 years ago, a large iron body broke up and struck the Gran Chaco region of what is now Santiago del Estero and Chaco provinces in Argentina. The impact gouged a field of craters, and indigenous peoples knew the iron long before European record — the name “Campo del Cielo” reflects their understanding that the metal came from the sky.

Structure & the Widmanstätten pattern

When cut, polished, and etched, Campo del Cielo reveals a Widmanstätten pattern — but because it’s a coarse octahedrite, the bands are wider and more open than the fine, delicate lattice of Gibeon or Muonionalusta. Many collectors leave Campo del Cielo as a natural fragment, prizing its rugged, rust-brown crust and irregular regmaglypt (thumbprint) surface rather than a polished face.

Campo del Cielo vs. Gibeon & Muonionalusta

For jewelry, the finer irons usually win. Compare in the Gibeon guide and Muonionalusta guide.

Collecting Campo del Cielo

Its low price and wide availability make Campo del Cielo the ideal starter specimen— you can own a genuine, several-thousand-year-old piece of space iron for very little. It’s sold as raw fragments, etched slices, cubes, and spheres. New to collecting? Start with our specimens collector’s guide, and always insist on a certificate of authenticity.

Care & rust prevention

Raw Campo del Cielo is iron and can rust readily, so keep it dry: store it with a sachet of silica gel, handle it with clean dry hands, and apply a thin film of oil or microcrystalline wax. Early surface rust comes off with isopropyl alcohol and a soft brush — full routine in the care & display guide. For a neutral scientific reference, see the Meteoritical Bulletin entry for Campo del Cielo.