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Northwest Africa 12899
Basic information Name: Northwest Africa 12899
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12899
Observed fall: No
Year found: 2017
Country: (Northwest Africa)
Mass:help 79 g
Classification
  history:
Recommended:  Eucrite    [explanation]

This is 1 of 471 approved meteorites (plus 1 unapproved name) classified as Eucrite.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 3 Jul 2020
Writeuphelp
Writeup from MB 109:

Northwest Africa 12899 (NWA 12899)

Northwest Africa

Purchased: 2017

Classification: HED achondrite (Eucrite)

History: A single stone weighing 77 g was found by an anonymous finder in Western Sahara and purchased in October 2017 at the Munich Fair for the collections of the Museo di Storia Naturale - SMA, University of Florence, Italy.

Physical characteristics: The main mass is partially covered by a black, shiny fusion crust with several cracks.

Petrography: (V. Moggi Cecchi, G. Pratesi, S. Caporali, UniFi): The thin section analyzed displays a basaltic texture. Orthopyroxene crystals, ranging in width from 80 to 160 μm are common, with minor clinopyroxene and anorthitic plagioclase. Low-Ca pyroxene crystals with fine (2-5 μm) pigeonite exsolution lamellae are diffuse. Minor phases are FeNi metal and troilite, with rare ilmenite and chromite grains.

Geochemistry: EMP (V.Moggi Cecchi, G.Pratesi, S.Caporali UniFi); Host: low-Ca pyroxene (Fs62.1±0.3En35.1±0.7Wo2.8±0.3; n=7; Fe/Mn = 34.0±0.2); Diopside exsolution lamellae in orthopyroxene (Fs27.5±0.2En28.7±0.3Wo44.0±0.2; n=8; Fe/Mn = 30.0±0.3); Calcic plagioclase An86.8±0.5Or0.6±0.5, n=9;

Classification: Eucrite with medium degree of shock and medium degree of weathering.

Specimens: The main mass, weighing 55 g, the type specimen, weighing 24 g, and one thin section are on deposit at MSN-FI (Inventory N G-75062).

Data from:
  MB109
  Table 0
  Line 0:
Place of purchase:Munich
Date:P 2017
Mass (g):79
Pieces:2
Class:Eucrite
Shock stage:moderate
Weathering grade:moderate
Ferrosilite (mol%):62.1±0.3 (N=8);27.3±0.5 (N=7)
Wollastonite (mol%):2.8±0.2;44.0±0.5;
Classifier:V. Moggi Cecchi, MSN-FI
Type spec mass (g):24
Type spec location:MSN-FI
Main mass:MSN-FI
Finder:Anonymous
Comments:Provisional name NWA 12899; Inventory # G75062; submitted by Vanni Moggi Cecchi
Institutions
   and collections
MSN-FI: MUSEO DI STORIA NATURALE DELL'UNIVERSITA' DEGLI STUDI DI FIRENZE Via Giorgio La Pira, 4 – 50121 FIRENZE, Italy; Website (institutional address; updated 14 Jan 2015)
UniFi: Università degli Studi di Firenze, P.zza S. Marco, 4 - 50121 Firenze, Italy (institutional address; updated 14 Sep 2013)
Catalogs:
References: Published in Meteoritical Bulletin, no. 109, in preparation (2020)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7354 approved meteorites from (Northwest Africa) (plus 1958 unapproved names)

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