Northwest Africa 18237 Ureilite - 482 g - (1)

Northwest Africa 18237
Basic information Name: Northwest Africa 18237
This is an OFFICIAL meteorite name.
Abbreviation: NWA 18237
Observed fall: No
Year found: 2024
Country: Mali
Mass:help 484 g
Classification
history:
Recommended: Ureilite [explanation]

This is 1 of 720 approved meteorites classified as Ureilite. [show all]
Search for other: Achondrites, Ureilites
Comments: Approved 6 Dec 2025
Writeuphelp
Writeup from MB 114:
Northwest Africa 18237 (NWA 18237)

Mali

Find: 2024

Classification: Ureilite

History: A single sample weighing 484 g was found in the Bir Ounane region of Mali by Hameti Mrabih in 2024.

Physical characteristics: The sample is rounded and brown exterior exhibiting orientation. Small patches of fusion crust are present on specimen The cut face has a protogranular and poikiloblastic texture composed of elongate grains that form a foliation.

Petrography: Description and classification (A. Love, App) Sample shows cumulate texture composed of equant to elongated -mm-sized olivine and pigeonite. Olivine and some pigeonite show metal bearing reduced margins at grain boundaries and fractures. Some grains show curvilinear trails of rounded troilite blebs. Additional minerals are: troilite, rare chromite and graphite.

Geochemistry: (A. Love, App) Olivine (Cores: Fa22.0±0.4, Fe/Mn=46.6±3.2, Cr2O3=0.6±0.0, CaO=0.3±0.0, n=14; rims Fa12.6±2.1, Fe/Mn= 24.8±5.2, Cr2O3=0.5±0.1, CaO=0.3±0.0, n=13); pigeonite (Cores: Fs19.5±0.2Wo9.5±0.1, Fe/Mn=28.2±0.9, n=6; rims: Fs8.3Wo19.8, Fe/Mn=10.9, n=1).

Classification: primitive achondrite (ureilite, U-S3, low weathering) Based on texture, mineral compositions, presence of graphite, sample is a ureilite.

Specimens: Salek Mrabih (Dominions meteors) holds the main mass. A polished mount and an endcut weighing 21.5 g are on deposit at App.

Data from:
MB114
Table 0
Line 0:
Origin or pseudonym: Bir Ounane DCA
Date: 2024
Mass (g): 484
Pieces: 1
Class: Ureilite
Shock stage: U-S3
Weathering grade: low
Fayalite (mol%): 17.5±5.0
Ferrosilite (mol%): 17.9±4.2
Wollastonite (mol%): 11.0±3.9
Classifier: A. Love, App
Type spec mass (g): 21.5
Type spec location: App
Main mass: Salek Mrabih
Finder: Hameti Mrabih
Comments: Submitted by Anthony Love