Khatyrka (meteorite)

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Coordinates: 62 ° 39 ′ 11.36 ″  N , 174 ° 30 ′ 1.54 ″  O Khatyrka is a stone meteorite from the class of carbonaceous chondrites of the CV3 type. He was found in July 2011 in the Chukchi Autonomous Okrug in Russia's Far East Federal District . The fall of the meteorite was not observed.

A total of 10 fragments of the meteorite were found, all of which are less than a millimeter in size and whose total weight is less than 0.1 g. Three of the pieces are on hold at the Smithsonian Institution for representative purposes .

Find history

The first three fragments of the meteorite were found during a first expedition in 1979 on the river Chatyrka (English Khatyrka ). It was a chance find while searching for platinum . These fragments finally came to Florence in Italy via traders and smugglers . In 2010 the mineral icosahedrite was discovered in them . The peculiarity of this mineral lies in its crystal structure , which does not obey any translation symmetry , but rather forms quasicrystals . These first meteorite fragments (grains) are kept in Saint Petersburg in Russia and Florence.

A team made up of the Russian, American and Italian scientists PJ Steinhardt, C. Andronicos, L. Bindi, VV Distler, M. Eddy, A. Kostin, V. Kryachko, GJ MacPherson, WM Steinhardt, and M. Yudovskaya led in From July 20 to August 7, 2011, a second expedition was carried out in the Chukchi region in order to find additional samples of the extremely rare mineral. A total of around 1.5 tons of clay minerals and other material were prospected along the Listventovyi River . Seven more pieces of a chondrite were found in the heavy mineral concentrates .

Petrography

As a carbonaceous chondrite of type CV3, Khatyrka consists of an undifferentiated, unequilibrated matrix with a high proportion of carbon (C) and clearly visible silicate spheres ( chondrules ) as well as traces of water and organic substances (V3) according to the classification according to van Schmus and Wood .

The examined meteorite grains are dark gray in color and contain various metals. The analysis with the scanning electron microscope on the polished surfaces of two grains revealed a porphyry composition of the meteorite rock with isolated olivine crystals in a porous matrix of fine-grain olivine as well as calcium-rich clinopyroxene, nepheline and various nickel-iron metals or sulfides. Aluminum-copper alloys could also be observed.

Khatyrka as a type locality

Khatyrka considered as type locality for the minerals cupalite , Decagonit , Hollisterit , Ikosaedrit , khatyrkite , Kryachkoit , Steinhardit and Stolperit . With the decagonite, the second mineral that forms quasicrystals was discovered.

Could addition of in the meteorite solid aluminum , iron , copper and nickel as well as the minerals Ahrensit , Awaruit , chromite , Coesite , Diopside , Enstatite and clino-enstatite , forsterite and other minerals of the olivine , hematite , Hedenbergit , Hercynit , corundum , magnetite , Naquit , Nepheline , pentlandite , sodalite , spinel , stishovite , suessite , taenite , trevorite , troilite and xifengite can be detected.

literature

  • Alex Ruzicka, Jeffrey N. Grossman, Laurence Garvie: The Meteoritical Bulletin . In: Meteoritics & Planetary Science . tape 49 , no. 100 , June 2014, p. E1 – E101 ( usra.edu [PDF; 896 kB ; accessed on March 11, 2018]).

Web links

Individual evidence

  1. ↑ a b Meteoritical Bulletin Database - Khatyrka. Retrieved April 16, 2018 .
  2. ↑ Quasicrystal: Meteorite brought an exotic structure to the earth. In: Spiegel Online. 2012, accessed April 16, 2018 .
  3. ^ Philipp Heck: Lexicon Astronomy - Meteorite: Classification. December 20, 2006, accessed April 16, 2018 .