Easily the most beautiful of the stony-iron meteorites; when cut and polished, pallasites consist of olivine crystals as large as 1cm across which are normally embedded in a nickel-iron mix. When cut and etched, the metal may exhibit Thomson Structures also called a Widmanstattan pattern. This is due to the accepted theory that pallasites are formed when large bodies of rock (called planetesimals) are in a molten state due to impacting one another. These impacts cause a disruption in the core and mantle and this area of combined materials is believed to make up pallasite meteorites.
The Imilac meteorite, like all other pallasites is a stony-iron composite which was found by westerners in the Atacama Desert, Chile in 1822. Said to be the second driest region in the world next to Antarctica, this area is extremely desolate and located on the leeward side of the western, coastal mountain range. Unlike other deserts, this desert is very cold with average temperatures ranging from only 32° - 75°F. As far as pallasites go, the Imilac is noted as being one of the most well-structured and stable meteorites.