Djoua 001: 28.045°N, 8.163°E
Place of discovry: Illizi, Algeria
Date of discovery: 2021 Feb
Classification: Enstatite achondrite (Aubrite)
History: Scattered pieces of a very large, pale colored achondrite were found in February and March 2021 purportedly near Djoua, Algeria. Several small pieces were obtained by Ali Benamar, and three larger pieces were purchased by Aziz Zad in April 2021 from a dealer in Ouargla, Algeria. Additional material was acquired from Algerian dealers by Marcin Cimala and Habib Naji in May 2021 and by Mark Lyon (in collaboration with Craig Zlimen and Roberto Vargas) in July 2021.
Physical characteristics: Exterior surfaces of the stones have black coatings in places which may be degraded fusion crust. Interiors are overall mottled beige and gray in color with sporadic small dark and rusty spots. Rare tiny grains of fresh metal are visible on polished pieces. Some large whitish grains (enstatite) are up to 1.5 cm across.
Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Very coarse grained unbrecciated aggregate of predominantly enstatite with accessory diopside, daubreelite, Ti-Cr-bearing troilite and rare Ni-poor kamacite. No plagioclase was found in the studied slice or endcut.
Geochemistry: Enstatite (Fs0.1±0.3Wo0.7±0.1, range Fs0.0-0.8Wo0.6-1.0, N = 6), diopside (Fs0.3±0.5Wo44.9±3.4, range Fs0.0-0.9Wo48.3-41.9, N = 3), troilite (Ti 2.9 wt.%, Cr 0.3 wt.%), Ni-poor kamacite (Ni 1.5-2.2 wt.%, Si 0.02-0.08 wt.%, N = 4).
Specimens: 138 g (26 g of which was donated by A. Benamar) including a polished slice and small polished endcut at UWB; remaining material with A. Zad and WangZ (8250 g), M. Cimala (1830 g), M. Lyon (3700 g in two pieces), C. Zlimen (2580 g), R. Vargas (120 g) and H. Naji (6014 g).
Mass (g): 22506
Pieces: several
Shock stage: low
Weathering grade: low
Classifier: A. Irving, UWS, and P. Carpenter, WUSL
Main mass: WangZ, A. Zad, M. Cimala, M. Lyon, C. Zlimen, R. Vargas, H. Naji
