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Northwest Africa 11778
Basic information Name: Northwest Africa 11778
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 11778
Observed fall: No
Year found: 2013
Country: (Northwest Africa)
Mass:help 768 g
Classification
  history:
Meteoritical Bulletin:  MB 107  (2018)  H5
Recommended:  H5    [explanation]

This is 1 of 10803 approved meteorites (plus 19 unapproved names) classified as H5.   [show all]
Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 24 Jul 2018
Writeuphelp
Writeup from MB 107:

Northwest Africa 11778 (NWA 11778)

(Northwest Africa)

Purchased: June 2013

Classification: Ordinary chondrite (H5)

History: Purchased by WrocU, Faculty of Geoengineering, Mining and Geology from Moroccan dealer in Zagora; 120 g was cut off and analyzed in thin section; 16.5 g of sample was powdered and for bulk chemistry.

Physical characteristics: Single stone (767.5 g) covered by black (with slight brown shade) fusion crust, 0.5 mm thick.

Petrography: (T.A. Przylibski, K. Luszczek, UTWroc) Chondrules (75 vol.%) include BO, PO, GO, RP, POP, and C types. Chondrules are mostly well defined and often have sharp edges. Chondrule diameters are from 0.2 to 1.2 mm, average 600±290um. One compound chondrule is 6.7 mm. Devitrified, partly crystallized mesostasis. Opaque minerals (20 vol.%) include troilite, kamacite and taenite, and rare chromite. Small feldspar grains discernible in electron images. Accessory apatite crystals. Matrix (5 vol.%) is fine-grained, crystalline and transparent, composed mostly of olivine crystals. Around 25% of low-Ca pyroxene crystals are twinned, some of them showing inclined extinction. Some olivine and pyroxene crystals show undulatory extinction. Irregular veins and cracks are filled with opaque iron oxides and hydroxides. Some grains of kamacite are weathered on edges.

Geochemistry: (R. Kryza, WrocU; T.A. Przylibski, K. Luszczek, UTWroc) Olivine Fa 18.0±0.0 (n=6); Pyroxene Fs13.2±0.0Wo 1.1 (N=12); Chromite (Mg0.3 Fe2+0.38 Mn0.03 Zn0.01 Si0.19 Ti0.02 Ca0.01)(Al0.27 Fe3+0.38 Cr1.27)O4; kamacite (5.85 wt%), taenite (from 40.4 to 52.7 wt%). Bulk chemistry (in wt%): Si 15.69, Al 0.99, Fe 29.74, Mg 12.42, Ca 1.19, Na 0.55, K 0.07, Ti 0.05, P 0.12, Mn 0.22, Cr 0.34, Ni 1.81, C 0.07, S 2.04; (in ppm) Ba 8, Co 961.2, Ga 4.8, Hf 6, Nb 0.3, Rb 1.5, Sr 15.2, V 64, Mo 1.3, Cu 93.5, Pb 0.1, Zn 10, As 0.7, Se 9.1, Zr 253.4, Au 207.3, Y 15.7, La 0.6, Ce 0.8, Pr 0.13, Nd 0.6, Sm 0.19, Eu 0.04, Gd 0.25, Tb 0.05, Dy 0.26, Ho 0.07, Er 0.18, Tm 0.02, Yb 0.18, Lu 0.02

Classification: Ordinary chondrite, H5, S2, W1.

Data from:
  MB107
  Table 0
  Line 0:
Place of purchase:Morocco, Zagora
Date:P June 2013
Mass (g):767.5
Pieces:1
Class:H5
Shock stage:S2
Weathering grade:W1
Fayalite (mol%):18.0±0.0 (N=6)
Ferrosilite (mol%):16.2±0.0 (N=12)
Wollastonite (mol%):1.1
Classifier:T.A. Przylibski, K. Luszczek, R. Kryza, WTWroc
Type spec mass (g):120
Type spec location:USil
Main mass:USil
Comments:Submitted by Katarzyna Luszczek
Institutions
   and collections
TM: Geoscience Museum, Transvaal Museum, P. O. Box 413, Pretoria 0001, South Africa (institutional address; updated 3 Mar 2011)
USil: Earth Sciences Museum, Institute of Earth Sciences, Faculty of Natural Sciences, University of Silesia in Katowice, B?dzi?ska 60, Sosnowiec, 41_200, Poland; Website (institutional address; updated 22 Nov 2020)
UTWroc: Wroclaw University of Technology, Faculty of Geoengineering Mining and Geology, Institute of Minings, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland (institutional address)
WrocU: Wroclaw University, Institute of Geological Sciences, ul. Cybulskiego 30, 50-205 Wroclaw, Poland (institutional address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 107, MAPS 55, 460-462
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 8138 approved meteorites from (Northwest Africa) (plus 1941 unapproved names)

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