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Northwest Africa 12776
Basic information Name: Northwest Africa 12776
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12776
Observed fall: No
Year found: 2015
Country: (Northwest Africa)
Mass:help 64 g
Classification
  history:
Meteoritical Bulletin:  MB 108  (2020)  Eucrite
Recommended:  Eucrite    [explanation]

This is 1 of 513 approved meteorites (plus 1 unapproved name) classified as Eucrite.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 11 Oct 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12776 (NWA 12776)

(Northwest Africa)

Purchased: 2015

Classification: HED achondrite (Eucrite)

History: Catalogued in ROM as sample LM57789.

Physical characteristics: Visible fusion crust showing low to moderate weathering, evident by a light orange coloring. Cracks in the fusion crust filled in with caliche or oxides. Interior of the sample fresh, showing coarse grained cummulate texture. Only slight weathering in the sample’s inside.

Petrography: Cumulate rock with equilibrated texture, not brecciated, no clasts, containing Opx, Cpx and plagioclase laths; equilibrated texture. No clasts noted. Low shock deformation.

Geochemistry: Mineral composition and geochemistry: Plagioclase An89.8±0.4 (n=16). Low-Ca pyroxene composition: Fs39.0±2.0Wo7.4±3.5 and Mg# 37.1-39.6 (n=11); high-Ca pyroxene composition: Fs20.5±6.4Wo40.5±11.9, Mg# 40.8-50.9 (n=18)

Classification: (A. Cernok, ROM) Texture and compositions suggest the sample is a cummulate, gabbroic eucrite.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Tucson Gem and Mineral Show
Date:P 2015
Mass (g):64.03
Pieces:2
Class:Eucrite
Shock stage:low
Weathering grade:low
Ferrosilite (mol%):39.0±2.0, 20.5±6.4
Wollastonite (mol%):7.4±3.5, 40.5±11.9
Classifier:A. Cernok, ROM
Type spec mass (g):12.9
Type spec location:ROM
Main mass:DGregory
Comments:Submitted by V. Di Cecco, ROM
Institutions
   and collections		 ROM: Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada (institutional address; updated 18 Oct 2011)
DGregory: David Gregory, 230 First Avenue, Suite 108, St. Thomas, Ontario N5R 4P5, Canada (private address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
Find references in NASA ADS:
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Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7885 approved meteorites from (Northwest Africa) (plus 1958 unapproved names)

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