NWA 4478 (LOD br.)


Mój pierwszy lodranit w kolekcji!

ep 0.75 g

NWA 4478 (LOD br.)


Name: NWA 4478 (Northwest Africa 4478)
Type: achondrite, LOD br. (lodranite breccia)
Date of find: September 2006
Total mass: 444g (two stones 298 and 146 gram)
Place: Algeria
NWA 4478 (LOD br.) main mass

MB: 92
History: Purchased by Greg Hupé in September 2006 from a Moroccan dealer in Zagora.
Physical characteristics: Two dense, brown stones (298 g and 146 g) lacking fusion crust.
Petrography: (A. Irving and S. Kuehner, UWS) This unusual specimen is a breccia composed of mineral and polycrystalline clasts (up to 8 mm across) with interstitial comminuted debris of the same phases. Large mineral clasts consist of either olivine or orthopyroxene (with clinopyroxene exsolution lamellae associated with blebs of Ni-free iron metal). The lithic clasts consist mainly of coarse interlocking olivine grains (up to 3 mm across) and sparse large chromite grains with interstitial (apparently intercumulus) clinopyroxene (some with orthopyroxene exsolution lamellae), orthopyroxene, kamacite, pyrrhotite, pentlandite and troilite. The modal abundance of metal (+limonite after primary metal) measured by BSE imaging on a large polished slice is 5vol.%. Plagioclase is absent. Olivine grains contain numerous blebby to worm-like polycrystalline inclusions composed of clinopyroxene+chromite+orthopyroxene+pentlandite, and clinopyroxene grains contain similar inclusions composed of orthopyroxene+chromite+kamacite; some examples exhibit symplectitic intergrowths of these various phases. Some olivine grains contain multiple blade-like lamellae of another olivine phase with different composition. Narrow elongate zones or discontinuous veinlets of metal are present within clinopyroxene, and adjacent to such metal the pyroxene has a more magnesian composition.
Geochemistry: Olivine (Fa10.6–10.9, FeO/MnO=22.1–23.9), olivine lamella in olivine (Fa9.8), clinopyroxene (Fs3.9Wo41.9, FeO/MnO=10.2), orthopyroxene lamella in clinopyroxene (Fs9.1Wo1.3, FeO/MnO=11.9), chromite (Cr/(Cr+Al)=0.822–0.825, Mg/(Mg+Fe)=0.506–0.520, TiO2=0.31–0.37wt.%). Oxygen Isotopes (D. Rumble, CIW): quadruplicate analyses of acid-washed silicate material by laser fluorination gave, respectively, δ18O=2.23, 2.43, 2.23, 2.40; δ17O=0.14, 0.30, 0.07, 0.11; Δ17O=–1.034, –0.984, –1.107, –1.147 per mil.
Classification: Achondrite (lodranite breccia). Primary clast textures, grain sizes, mineral compositions and oxygen isotopic compositions indicate that this specimen is a lodranite, and represents the first known brecciated example. The polyphase inclusions within mafic minerals are similar to those described in lodranite-like achondrite QUE 93148 by Goodrich and Righter (2000); along with the lamellae in olivine and metal-rich zones within pyroxene, these features may indicate an episode of reduction after the formation of the primary assemblage.
Specimens: A total of 20.1 g of sample and one polished thin section are on deposit at UWS. Mr. G.M. Hupé holds the main mass.

Co na temat sprzedawanych fragmentów NWA 4478 pisa³ Greg Hupe na eBay'u:

NWA 4478 Brecciated Lodranite Meteorite
The World’s First Brecciated Lodranite!

This impossibly rare meteorite was first discovered in September 2006 and consists of two stones totaling just 444 grams, the official Total Known Weight (TKW). My brother, Greg waited over a year so the scientists could perform a magnitude of tests to unlock the amazing details of this very collectible meteorite. Lodranites are extremely rare with only a handful discovered to date (most are unobtainable Antarctic specimens), making NWA 4478 one of the rarest meteorites ever discovered! While non-brecciated lodranites are demanding up to $1,000.00 per gram or more, NWA 4478 "Brecciated" lodranite is priced well below that, providing an excellent value. This incredible meteorite polishes to a high luster. Every specimen comes with an identification card from the Hupé Collection.

Link to published Meteoritical Society abstract on NWA 4478: http://www.lpi.usra.edu/meetings/metsoc2007/pdf/5129.pdf

Beautiful image of 16.7 gram complete slice: http://www.lunarrock.com/nwa4478/nwa4478slice.jpg

Image of 93.6 gram Main Mass: http://www.lunarrock.com/nwa4478/nwa4478mainmass.jpg

Optical thin section image in cross-polarized light: http://www.lunarrock.com/nwa4478/nwa4478ts.jpg


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Page update: 2020-06-07 00:50