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Northwest Africa 12578
Basic information Name: Northwest Africa 12578
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12578
Observed fall: No
Year found: 2018
Country: Morocco
Mass:help 415 g
Classification
  history:
Meteoritical Bulletin:  MB 108  (2020)  LL6
Recommended:  LL6    [explanation]

This is 1 of 2843 approved meteorites (plus 1 unapproved name) classified as LL6.   [show all]
Search for other: LL chondrites, LL chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 26 Apr 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12578 (NWA 12578)

Morocco

Purchased: 2018 Apr

Classification: Ordinary chondrite (LL6)

History: One fresh-looking crusted piece was purchased in Zagora, Morocco, by Sergey Vasiliev from a Moroccan meteorite dealer in April 2018. After purchase, the piece was broken into 2 pieces.

Physical characteristics: Total mass of one piece is about 415 g. Fusion crust is partially preserved. The interior of the meteorite is greenish gray whereas surface is dark brown.

Petrography: (Pavel Yu. Plechov, FMMR). Olivine and Low-Ca pyroxene are equilibrated and chondrules are indistinct or absent. Rare relics of barred-olivine chondrules have size from 500 to 700 µm. Low-Ca Px grains have rounded shape (size 150-250 µm) and very uniform composition (about Fs25). Metal consists of kamacite and taenite (with 44-45 wt.% Ni). Plagioclase grains (An10.6) are about 50 μm or more. These features indicate petrological type 6 for the meteorite. Olivine has no undulatory extinction, and the absence of opaque shock veins and melt pockets indicates a shock stage of S1. Olivine, pyroxene and metal are fresh and unweathered (weathering grade W0).

Geochemistry: Mineral composition and Geochemistry: EDS-WDS analyses (Pavel Yu. Plechov, FMMR). The primary chondrite paragenesis includes olivine Fa30.59±0.22 (N=20), orthopyroxene Fs24.9±0.4Wo2.34±0.14 (N=18), plagioclase Ab84.7An10.6Or4.3 (N=8), Cr-bearing clinopyroxene En46.0Fs10.8Wo43.1 (N=5), chromite Crt77.9Spl8.9 (N=4). Phosphates are both Cl-apatite and merrillite. Composition of kamacite (in wt.%, N=3): Fe 88.8, Ni 4.2, Co 7.0 (measured by WDS). Taenite (N=2) contain 44.5 and 2.1 wt.% of Ni and Co respectively. Troilite is close to ideal FeS.

Classification: Ordinary chondrite. LL6, S1, W0.

Specimens: Sergey Vasiliev holds one piece about 240 g. Another piece (166 g) and thin section, FMMR.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Zagora
Date:P 2018 Apr
Mass (g):415
Pieces:2
Class:LL6
Shock stage:S1
Weathering grade:W0
Fayalite (mol%):30.59±0.22 (N=20)
Ferrosilite (mol%):24.9±0.4 (N=18)
Wollastonite (mol%):2.34±0.14 (N=18)
Classifier:Pavel Yu. Plechov, FMMR
Type spec mass (g):166
Type spec location:FMMR
Main mass:Sergey Vasiliev
Comments:Submitted by Pavel Yu. Plechov
Institutions
   and collections
FMMR: Fersman Mineralogical Museum, Leninskiy prospekt 18 korpus 2, Moscow, Russia, 119071, Russia; Website (institutional address; updated 24 Feb 2018)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 1743 approved meteorites from Morocco (plus 26 unapproved names) (plus 1 impact crater)

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