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Dimensions: 85.6 x 63.7 x 50.3 mm max.
Name: NWA 14092 AURE
Class: Ureilite
Country: MOROCCO
Date of Find/Purchase: 2012
Reference: Wikipedia, the free encyclopedia
Ureilite is a rare type of stony meteorite that has a unique mineralogical composition very different from that of other stony meteorites. This dark grey or brownish meteorite type is named after the town Novo Urei (54° 49' N, 46° 0' E), Mordova Republic of Russia, where a meteorite of this type fell on 4 September 1886. Notable ureilites are the Novo Urei and the Goalpara, also named for the town in which it landed (Goalpara, Assam India). On 7 October 2008, tiny asteroid 2008 TC3 entered the Earth's atmosphere and exploded an estimated 37 kilometers (23 mi) above the Nubian Desert in Sudan. Fragments of this asteroid were recovered the following December and were found to be ureilite.
Composition
A technical name for ureilite would be olivine-pigeonite achondrite. Ureilites are noted for containing microscopic nano-diamonds only a few microns in diameter. Compared to most other meteorites, ureilites tend to have a high percentage of carbon (up to 2% by weight) in the form of nano-diamonds and graphite.[1] The diamonds are probably the result of high pressure shockwaves produced by collisions of the ureilite parent body with other asteroids. Ureilites can be divided into two subcategories: monomict and polymict. Monomict ureilites are coarse grained olivine with minor pyroxene traces. Polymict ureilites are a mixture of clasts of dissimilar composition.
A typical ureilite contains olivine and pyroxene (pigeonite, augite, or orthopyroxene) crystals, up to several millimeter across, embedded in a dark carbon-rich matrix of graphite and tiny diamond, low-nickel iron metal, troilite (iron sulfide), and iron carbide.
Origin
Unknown. Some groups of meteorites come from a single object (ie. Mars, Moon, 4 Vesta), but there has been no parent body found as yet for the ureilites. It is probable that their origin is a C-type asteroid. It remains unclear whether ureilites originated on different parent bodies or in different regions of a single body. They could even have originated within the Solar Nebula, which would make them the most primitive Achondrites.The presence of diamonds, which can form from graphite as a result of severe shock metamorphism, hints at a violent impact history.
One single stone of 371 g was purchased in 2012 in Agadir, Morocco, probably found near the Algerian border in the Sahara Desert.
The stone is beautiful cone shaped and shows some thin intact fusion crust and desert varnish. A probe of 29 g for a type mass sent for analysis and classification to Jérôme Gattacceca of CEREGE in FRANCE.
Petrography: (J. Gattacceca, CEREGE) Blocky assemblage of olivine and low-Ca pyroxene with 800 µm grains size. Metal weathering products are found along grain rims. Metal is found as µm sized grains enclosed in silicates. Abundant carbon material is present.
Geochemistry: Olivine Fa20.1±0.6, CaO 0.39±0.02 wt%, FeO/MnO = 50.1 (n=3). Olivine reduced rim Fa2.9 (n=1)Low-Ca pyroxene Fs17.6±0.4, FeP/MnO = 30.7±2.7 (n=6).
The Main Mass of 305.1 g is held by Norbert Kammel of ROCKS ON FIRE, in Noble Park Nth., Victoria, Australia.
Here you surely not only have an interesting and fascinating rock, but also a VERY RARE one.
This meteorite is a piece from out of this world, more than 4.5 billion years old, your own little Piece of Heaven!