Aubrites
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Aubrite
Country
United States of America
Year found
1919
Mass
17 kg
[Museum Collection]
(1) 11.82g
CHRISTIE'S Auction 9-23 Feb 2022 Lot#33 National Museum of Natural History / Smithsonian Institution
CHRISTIE'S Auction 9-23 Feb 2022 Lot#33 National Museum of Natural History / Smithsonian Institution
CHRISTIE'S Auction (9-23 Feb 2022)Lot#33
Provenance: National Museum of Natural History / Smithsonian Institution
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Aubrite
Country
Algeria
Year found
2021
Mass
22.51 kg
[Museum Collection]
(1) 15.08g (2) 26.65g (3) 10.12g (4) 6.64g
(5) 2.98g
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). Classification: Aubrite. 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).
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Aubrite-an
Country
Australia
Year found
1941
Mass
22 kg
[Museum Collection]
(1) 2.471g (2) 1.394g (3) 1.055g (4) 1.054g (5) 1.017g (6) 0.238g (7) 10g(14pieces)
(8) 1.49g(12pieces) (9) 1.31g(8pieces)
(10) 1.24g(11pieces) (11) 1.17g(11pieces)
(12) 1.10g(7pieces)
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Aubrite
Country
Mali
Year found
2022
Mass
17 kg
[Museum Collection]
(1) 37.88g (2) 13.05g (3) 3.06g
History: This meteorite was found in late March 2022 in the region of "Wad Alhath" in Mali, about 54 km northeast of the village of Tamanieret and 245 km southeast of Taoudenni, by Sahrawi meteorite hunters. The total recovered amount was approximately 17 kg. Bachir Salek obtained 12.5 kg, including the main mass, which weighs 3550 g. Physical characteristics: This meteorite consists primarily of clusters of coarse, interlocking enstatite crystals with a pegmatitic texture. Individual crystals are cm-sized, many showing distinct cleavage planes and traces. Some enstatite crystals are milky-white in color, while a few are colorless translucent to transparent and gemmy. The enstatite crystals separate from the clusters easily, and the largest single crystal weighed 45 grams and was approximately 5 cm long and 2 cm wide. There are also scattered dark-colored patches on some of the crystals. Significant amounts of smooth cream-colored to white fusion crust are visible, although some fusion crust is dark-colored. No vesicles are present. The meteorite appears to be unbrecciated. Petrography: (A. Ross and C. Agee, UNM) Electron microprobe analyses and reflected light microscopy show that enstatite makes up approximately 98% of this meteorite. Scattered small diopside grains were detected. A single olivine grain was found in the sample microprobe mount. Small grains of kamacite, taenite, schreibersite, Ti-troilite, troilite, and daubreelite were the only accessory opaques observed. No other sulfides were detected. No feldspar was found in the microprobe mount. Geochemistry: (A. Ross, UNM) Enstatite Fs0.0±0.0Wo0.9±0.1, n=6; diopside Fs0.0±0.0Wo45.5±0.8, n=3; forsterite Fa0.0, n=1; kamacite Ni=4.3±0.8, Co=0.4±0.2 (wt%); taenite Ni=48.7, Co=0.11 (wt%). Classification: Aubrite, non-brecciated (after Keil, 1989). This aubrite has one of the highest modal abundances of enstatite ever reported (~98%). The enstatite, diopside, and forsterite of this meteorite have some of lowest iron contents (below electron microprobe major element detection limits) ever documented in an aubrite. Specimens: 216 g on deposit at UNM, Bachir Salek holds the main mass.
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Aubrite
Country
Morocco
Year found
2006
Mass
906 g
[Museum Collection]
(1) 2.0g
History and physical characteristics: Sixty-one pieces with a total weight of 906 g were purchased in Tagounite, Morocco in May 2007. Most of the stones are medium to dark brown with some remnant fusion crust. Petrography: (T. Bunch and J. Wittke, NAU) A brecciated cumulate rock with clasts as large as 2 cm. The intact lithology is dominated by subhedral to anhedral polysynthetically twinned enstatite with fine-grained intercumulus intergrowths of feldspathic glasses and a silica phase. Other minerals include graphite, FeS, daubreelite, schreibersite, niningerite, perryite as exsolution lamellae in Si-bearing kamacite and Zn-bearing brezinaite. Large clasts show a multitude of sub-parallel, closely spaced compression fractures. Shock level is S3 and the weathering grade is W5 for small pieces (
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Aubrite
Country
(Northwest Africa)
Year found
2019
Mass
564 g
[Museum Collection]
(1) 7.45g (2) 4.16g (3) 2.47g
History: Purchased by Zaid Sbitti in November 2019 from a dealer in Ouargla, Algeria. Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Breccia composed of large clasts of enstatite (with diopside exsolution lamellae) and subordinate forsterite set within a finer grained matrix composed of enstatite, sodic plagioclase, Cr-troilite, niningerite and Si-bearing kamacite. Geochemistry: Enstatite (Fs0.0-0.1Wo0.9-1.1, N = 2), diopside (Fs0.0-0.1Wo44.4-45.8, N = 2), forsterite (Fa0.0±0.0, N = 2), plagioclase (Ab86.1An0.5Or13.4), kamacite (Ni = 3.0 wt.%, Si = 3.1 wt.%), troilite (Cr = 2.8 wt.%). Classification: Aubrite. Specimens: 24.7 g in the form of a polished endcut at UWB; remainder held by Mr. L. Ouabicha and Mr. Z. Sbitti.