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Northwest Africa 12855
Basic information Name: Northwest Africa 12855
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12855
Observed fall: No
Year found: 2014
Country: (Northwest Africa)
Mass:help 224 g
Classification
  history:
Recommended:  H3    [explanation]

This is 1 of 594 approved meteorites (plus 2 unapproved names) classified as H3.   [show all]
Search for other: H chondrites, H chondrites (type 3), Ordinary chondrites, and Ordinary chondrites (type 3)
Comments: Approved 9 Aug 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12855 (NWA 12855)

(Northwest Africa)

Purchased: 2014

Classification: Ordinary chondrite (H3)

History: Collected by nomads in Western Sahara and purchased by Parco Astronomico delle Madonie from Giorgio Tomelleri in 2018.

Physical characteristics: A black crust-covered single piece weighing 224 g. Several well-formed chondrules are visible on the cut surface

Petrography: (V. Moggi Cecchi, G. Pratesi, UniFi); A marked chondritic texture is visible in the thin section displays, with PO, PP and POP chondrules ranging from 300 to 1200 μm in a fine grained matrix. Olivine and orthopyroxene crystals PO and POP chondrules are inhomogenesous, with a slight core-rim variability. Olivine is more Fe-rich in the matrix. Opaque phases are diffuse and mainly represented by iron oxides, Fe-Ni alloys and troilite as individual grains scattared in the matrix or rimming chondrules.

Geochemistry: EMP (V. Moggi Cecchi, G. Pratesi, UniFi); Olivine (Fa12.4±9.5Fo87.6±5.5; Fe/Mn = 42.0, n=24 ); Orthopyroxene in chondrules’ grains and in matrix (Fs10.4±6.9En88.5±3.3Wo0.9±0.1, Fe/Mn = 25.2, n=15);

Classification: Ordinary Chondrite (H3); S1; W3

Specimens: A total of 20.1 g specimen is on deposit at MSN-FI. Parco Astronomico delle Madonie holds the main mass.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Erfoud
Date:P 2014
Mass (g):224
Pieces:1
Class:H3
Shock stage:S1
Weathering grade:W3
Fayalite (mol%):12.4±9.5 (n=24)
Ferrosilite (mol%):10.4±6.9 (n=7)
Wollastonite (mol%):0.9±0.1
Classifier:V. Moggi Cecchi, G. Pratesi, MSN-FI
Type spec mass (g):20.1
Type spec location:MSN-FI
Main mass:Parco Astronomico Madonie - Isnello
Finder:Anonymous
Comments: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. 108, in preparation (2019)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6877 approved meteorites from (Northwest Africa) (plus 2037 unapproved names)

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