• Type: Iron meteorite / IIIE-an
• Location: Xinjiang, China
• Weight: 21.1g
• Size: 47 x 16 x 8 mm
• Year of discovery: 1898
• Known total weight: 74 tonnes
• Surface treatment: Cut and Polished on multiple sides
• DETAILED DESCRIPTION

Aletai Meteorite – The IIIE group's iron marvel The Aletai meteorite belongs to the IIIE group, which is a specific type of iron meteorite. This classification encompasses meteorites with certain chemical compositions and crystallographic structures. Meteorites in this group tend to exhibit an octahedrite structure, meaning that when cut and polished, they reveal the characteristic patterns known as Widmanstätten figures. IIIE meteorites, like Aletai, are characterized by the presence of kamacite (low-nickel iron) and taenite (high-nickel iron) bands forming the octahedrite pattern. Uniqueness of the Aletai meteorite Aletai is exceptional for having the highest concentration of gold among IIIE group meteorites and a significantly higher iridium concentration compared to others in the same group. Since the amount of iridium in meteorites is much higher than that in Earth's crust, the unusually high concentration of iridium found at the Cretaceous-Paleogene boundary 65 million years ago formed the basis of the theory that a massive meteorite impact may have been responsible for the extinction of the dinosaurs. Discovery and distribution The meteorite was discovered in 1898 in the Xinjiang region of China. The total mass found is estimated at about 74 tons. The largest fragment weighs 28 tons, making it the fifth-largest meteorite on Earth. The impact field covered an area of up to 500 kilometers, initially causing discrepancies in identification and naming. Different names such as Armanty and Ulasitai were later unified under the name Aletai after chemical analysis. Mineralogy and visual effects An interesting feature is that when the angle of light changes, the reflectivity of the main alloys changes, and the sample sparkles. This effect is typical for octahedrite structures, but Aletai is particularly spectacular due to the presence of mirror-bright inclusions of the mineral schreibersite. Schreibersite is considered the primary source of phosphorus, which may have played a crucial role in the origin of life on Earth. It is composed of iron-nickel phosphide, with colors ranging from bronze to silvery white. This mineral is commonly found in iron meteorites such as Magura (Slovakia), Sikhote-Alin (Russia), Gebel Kamil (Egypt), and São Julião de Moreira (Portugal). The name comes from the Austrian scientist Carl Franz Anton Ritter von Schreibers, one of the first to identify this mineral.