Meteoritical Bulletin: Entry for Northwest Africa 12722

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Northwest Africa 12722

Basic information

Name: Northwest Africa 12722
This is an OFFICIAL meteorite name.
Abbreviation: NWA 12722
Observed fall: No
Year found: 2018
Country: (Northwest Africa)
Mass: 68 g

Classification
history:

Recommended:

CK3 [explanation]

This is 1 of 71 approved meteorites classified as CK3. [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), CK chondrites, CK3 chondrites, and CV-CK clan chondrites

Comments:

Approved 20 Dec 2021

Writeup

help

Writeup from MB 110:

Northwest Africa 12722 (NWA 12722)

(Northwest Africa)

Purchased: March 2018

Classification: Carbonaceous chondrite (CK3)

History: Collected by nomads in Western Sahara and purchased by Hichame Mimaghador at the Erfoud market from a Moroccan dealer.

Physical characteristics: A single piece weighing 68 g with traces of fusion crust.

Petrography: (V. Moggi Cecchi, L. Fabrizi, G. Pratesi, UniFi) The thin section displays a chondritic texture, with scattered PO and POP chondrules set in an abundant medium to grained matrix (60 vol% from point counting, n=520). Chondrules are often rimmed by opaque phases, mainly consisting of iron oxides, and range from 600-800 μm in dimensions. POP chondrules display unequilibrated fayalitic olivine and Mg-rich orthopyroxene crystals with minor diopsidic pyroxene; matrix is fine grained and almost entirely composed by fayalitic olivine mixed with Ca-rich pyroxene and albitic mesostasis; opaque phases are mainly represented by iron oxides and magnetite grains inside chondrules.

Geochemistry: EPMA (V. Moggi Cecchi, G. Pratesi, UniFi); Olivine (Fa_23.7±9.8Fo_76.4±8.2; Fe/Mn = 132.9, n=12 ); Orthopyroxene in chondrule grains and in matrix (Fs_13.9±7.2En_84.8±5.4Wo_1.3±0.1, Fe/Mn = 86.9, n=13); High-Ca pyroxene (Fs_9.6±1.6En_42.6±0.9Wo_47.7±0.4, n=5); plagioclase (An_15.1Or_4.9). Magnetite has 4.2 wt% Cr₂O₃ (n2). Oxygen isotopes: (I.Franchi, R.Greenwood, OU) δ¹⁷O = -2.46 permil, δ¹⁸O = 1.61 permil, Δ¹⁷O = -3.30 permil.

Classification: Carbonaceous chondrite (CK3).

Specimens: A total of 16 g specimen is on deposit at MSN-FI, Inv.# I3373. Mimaghador holds the main mass.

Data from:
  MB110
  Table 0
  Line 0:

Place of purchase:	Erfoud
Date:	P March 2018
Mass (g):	68
Pieces:	1
Class:	CK3
Shock stage:	moderate
Weathering grade:	W4
Fayalite (mol%):	23.7±9.8 (n=12)
Ferrosilite (mol%):	13.9±7.2 (n=13)
Wollastonite (mol%):	1.3±0.3
Classifier:	V. Moggi Cecchi, L. Fabrizi, G. Pratesi, UniFi
Type spec mass (g):	16
Type spec location:	MSN-FI
Main mass:	Ziyao Wang
Comments:	Field label Mima 51 (see provisional table). Inv.# I3373.; submitted by Vanni Moggi Cecchi

Plots:

O isotopes:

Institutions
and collections

OU: Planetary and Space Sciences Department of Physical Sciences The Open University Walton Hall Milton Keynes MK7 6AA United Kingdom, United Kingdom (institutional address; updated 8 Dec 2011)
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. 110, in preparation (2021)

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Geography:

Coordinates:

Unknown.

Statistics:
This is 1 of 8495 approved meteorites from (Northwest Africa) (plus 1899 unapproved names)

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