NWA 7325
NWA 7325 (official name Northwest Africa 7325 ) is an unusual achondritic stone meteorite that was found broken into 35 pieces in February 2012 in the Moroccan Sahara . It has a total mass of 345 grams and possibly comes from Mercury .
description
The meteorite is noticeable through a light green melting crust. The conspicuous fragments were acquired by the German meteorite dealer Stefan Ralew in April 2012 from a dealer in Erfoud , Morocco , and some of them were forwarded to the meteorite researcher Anthony J. Irving at the University of Washington in Seattle for investigation . NWA 7325 consists mainly of about 56 percent by volume of the feldspar plagioclase , 27 percent of the bright green silicate mineral chromium diopside and 16 percent of the silicate mineral olivine . It contains an unusually high amount of magnesium and calcium, but almost no iron. The rock shows relatively large crystals and evidently formed from a very hot and only slowly cooling melt on a larger celestial body with volcanic activity.
The chemical composition of NWA 7325 is clearly similar to the data obtained by the MESSENGER space probe from the surface of Mercury, which also contains virtually no iron. However, it appears to be rich in enstatite , while this silicate mineral is absent from the meteorite. Therefore, it is believed that the meteorite rock was ejected from a deeper layer of the planet by a large impact .
See also
Web links
- Tilmann Althaus: NWA 7325: A meteorite from Mercury? In: Spektrum.de, February 4, 2013
- Meteoritical Bulletin Database: Northwest Africa 7325. Retrieved June 28, 2015