Dear List Members, today I can present my new spectacular Sahara Iron. NWA 6583 - Iron ungrouped with some rare silicate inclusions (Enstatite and Diopside) in a polycrystalline iron textur.
------------------------------------------------------------------------------------------------------------ IMPORTANT!! For detailed informations: A great article over 18 pages you find in the MAPS (Meteoritics & Planetary Science) Volume48 / Number12 / 2013 December / Page 2451 to 2468 (18 pages ! ) ------------------------------------------------------------------------------------------------------------ Writeup from MB 100: Northwest Africa 6583 (NWA 6583) (Northwest Africa) Purchased: 2010 Oct Classification: Iron meteorite (ungrouped) History: A single iron mass was purchased from a Moroccan dealer in October 2010 by M. Graul, Bernau, Germany. Physical characteristics: The 1825 g mass, measuring 105 × 100 × 38 mm, has a flattened shape. The part embedded in soil (~40%) is covered by caliche, whereas the exposed surface is glossy-brown and presents 40-45 rounded depressions from 0.5 to 1 cm in diameter. Petrography: (M. D’Orazio, A. Fazio, DST-PI) Etched section shows a polycrystalline texture composed of roughly equiaxal grains (0.1 to 2 cm) of ataxitic Fe-Ni. The Fe-Ni grains have a martensitic texture. Rounded, twinned and polycrystalline inclusions of troilite, rosettes and isolated crystals of graphite, and large skeletal crystals of schreibersite are common. Silicates occur as isolated euhedral crystals of enstatite and rare forsteritic olivine, and as aggregates of enstatite with overgrowths of diopside or with troilite-rich reaction rims. Many troilite grains contain inclusions of several types of Mn-Mg-Fe-Zn-Cu sulfides. Melted crystals of schreibersite and troilite showing dendritic textures are present in the external portion of the section. Terrestrial weathering is low. Geochemistry: Composition of the metal (ICP-MS; D’Orazio and Folco, 2003) is Co=0.430, Ni=18.0 (both in wt%), Cu=1350, Ga=52, Ge=125, Ir=0.19, Au=1.13 (all in ppm). Composition of the silicates (all mol%): enstatite (En98.2±0.3Wo1.4±0.2), diopside (En51.6±1.0Wo47.8±0.6). Classification: Iron meteorite, ungrouped, with anomalous structure, silicate inclusions and low weathering. Specimens: A 60.5 g etched end cut is on deposit at DST-PI. MGraul holds the main mass. First Slices for sale I have listed on ebay. One from this slice is for auction and will ending in around 24 hours. I have listed some other rare irons too (Roundup, Maslyanino, NWA 6583 and much more) and other large and interesting NWA stones. All auctions you can find here: http://stores.ebay.com/Mirko-Graul-Meteorite/_i.html?rt=nc&_sc=1&_sid=18192829&_sticky=1&_trksid=p4634.c0.m14&_sop=1&_sc=1 All offers from NWA 6583 you can find here: http://stores.ebay.com/Mirko-Graul-Meteorite/_i.html?_nkw=NWA+6583&submit=Search&_sop=10&_sid=18192829&_sc=1 Best regards Mirko Mirko Graul Meteorite Quittenring.4 16321 Bernau GERMANY Phone: 0049-1724105015 E-Mail: [email protected] WEB: www.meteorite-mirko.de Member of The Meteoritical Society (International Society for Meteoritics and Planetery Science) IMCA-Member: 2113 (International Meteorite Collectors Association) ______________________________________________ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
