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achondrites

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Al Bir Lahlou 001

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

achondrite-ung

Country

Year found

2021

Mass

12.4 kg

[Museum Collection]

(1) 4.254g *This meteorite was donated to Natural History Museum Vienna.

(2) 2.64g   (3) 2.50g   

History: The stone was found by meteorite hunters in Western Sahara. Physical characteristics: Smooth sand blasted exterior and saw-cut, exposed interior show a cumulate intermingling of cream-colored plagioclase grains and vivid-green pyroxene grains. Petrography: (C. Agee and A. Ross, UNM) This meteorite contains approximately 60% plagioclase, 35% low-Ca pyroxene, minor phases include olivine, low-Ni iron metal, and Cr-spinel. Grain boundaries between plagioclase and pyroxene are gradational and occupied by blebby intergrowths of both phases. Olivine was observed as small (~100 μm) inclusions in pyroxene. Metal is nearly pure iron with trace amounts of cobalt -- nickel was barely detectable with the microprobe. Geochemistry: (A. Ross, UNM) Olivine Fa36.0±3.9, Fe/Mn=35±2, n=6; low-Ca pyroxene Fs28.6±2.7Wo3.6±0.9, Fe/Mn=22±1, Cr2O3=0.77±.14 (wt%), n=6; plagioclase An97.9±0.1Ab2.0±0.1Or0.1±0.0, n=4; iron metal Co=0.24±0.10 (wt%), n=5. Oxygen isotopes (K. Ziegler, UNM): 3 acid-washed fragments analyzed by laser fluorination gave δ18O= 3.821, 3.829, 3.939; δ17O= 1.723, 1.731, 1.792; Δ17O= -0.295, -0.291, -0.288 (linearized, per mil, TFL slope=0.528). Classification: Ungrouped achondrite. This meteorite is a norite. It has oxygen isotopes values that are about 0.05 per mil below the HED array. The pyroxene compositions are similar to that found in diogenites, however the plagioclase abundance (60%) of this norite is much higher than in any diogenite (orthopyroxenite). The anorthite (An98) content of the plagioclase is significantly higher than typical HED values. Specimens: 22 g including a probe mount on deposit at UNM, Said Bachir holds the main mass.

Erg Chech 002

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

achondrite-ung

Country

Year found

2020

Mass

31.78 kg

[Museum Collection]

(1)115.08g  (2)25.799g   (3)8.166g    (4)5.492g    (5)3.250g    (6)2.552g     (7)2.3261g  (8)2.222g    (9)1.941g    (10)1.895g   (11)1.813g   (12)1.684g (13)1.568g  (14)1.506g   (15)1.488g (16)0.568g
(17)2.8g      (18)1.62g      (19)2.87g    (20)1.95g (21)1.72g    (22)1.59g      (23)1.3g      (24)10.957g (25)1.75g 

• 分類:エイコンドライト • 発見隕石:2020年 • 落下国:アルジェリア • 発見総重量:31.78 kg • 同分類の隕石数:166個 • 地球のような層構造を持った天体の地殻から飛来した • 太陽系最古(45億66百万年前)の火山岩 【 監修 北海道大学 圦本尚義 】 • Achondrite-ung • Found 2020 • Algeria • Found 31.78 kg • one of 166 meteorites in this classification • This came from the crust of an earth-like layered object. • Oldest volcanic rock (4,566 million years ago) in the solar system 【Supervised by Prof. Hisayoshi Yurimoto, Hokkaido University】

Ksar Ghilane 022

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

Achondrite-ung

Country

Year found

2023

Mass

50 kg

[Museum Collection]

(1) 10.39 g

History: Found in Tunisia in 2023. Purchased by Adam Aaronson in February and November 2023 from a Libyan dealer. Portions of the material were subsequently provided to Craig Zlimen at the Tucson Gem and Mineral Show in February 2024, and in turn acquired by Robert Ward, Brian Caress and Ben Hoefnagels. Physical characteristics: A single large stone (25 kg) and many smaller pieces found with it. Most of the stones lack fusion crust and have mottled, dark and light gray granular exteriors. However, several pieces are partly coated by black fusion crust. The interiors of the stones have the appearance of equigranular aggregates of light gray and whitish grains. Petrography: (A. Irving, UWS, and P. Carpenter, WUSL) The specimen is composed predominantly (>90 vol.%) of almost end-member augite (mostly as equant grains, mean grainsize ~1.5 mm) accompanied by minor enstatite and accessory Cr-troilite, daubreelite, alabandite and an Mn-Fe oxide phase. Enstatite occurs as small irregular inclusions or sparse fine lamellae within augite grains, and different macroscopic colors of the augite grains apparently reflect differing concentrations of sulfide inclusions. Some secondary calcite veins are present throughout. Geochemistry: Augite (Fs0.0-0.1Wo39.4-42.3, N = 3), enstatite (Fs0.1±0.0Wo0.9-3.6, N = 3). Oxygen isotopes (K. Ziegler, UNM): analyses of acid-washed subsamples by laser fluorination gave, respectively, δ17O 3.018, 2.926; δ18O 5.781, 5.559; Δ17O -0.034, -0.009 per mil (all data linearized, TFL slope = 0.528). Classification: Achondrite (ungrouped, Mg-rich clinopyroxenite). This meteorite is texturally and mineralogically very similar to ungrouped augite-rich achondrite NWA 15915. but does not exhibit the same degree of irrational exsolution of enstatite from the dominant constituent augite. Terrestrial pairing is further excluded by the different physical appearance of these two meteorites, different degree of weathering, and the fact that their purported find sites are hundreds of kilometers apart. Both of these meteorites may have some affinities to aubrites, but differ in being composed predominantly of almost Fe-free augite rather than enstatite. Specimens: 41.3 g including one polished thin section at UWB; 677 g with Mr. R. Ward; 770 g with Mr. B. Caress; 674 g with Mr. B. Hoefnagels; 800 g with Mr. D. Dickens; remainder including the 25 kg main mass with Aaronson.

Zakłodzie

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

Enst achon-ung

Country

Year found

1998

Mass

8.68 kg

[Museum Collection]

(1) 2.97g

This is 1 of 5 approved meteorites classified as Enst achon-ung. Search for specimens in the Smithsonian Institution collection (U.S.): Search for this meteorite in the Natural History Museum collection (U.K.): Published in Meteoritical Bulletin, no. 84, MAPS 35, A199-A225 (2000)

NWA011

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

achondrite-ung

Country

Year found

1999

Mass

40 g

[Museum Collection]

(1) 1.103g   (2) 0.730g   

This is 1 of 134 approved meteorites classified as Achondrite-ung. Published in Meteoritical Bulletin, no. 84, MAPS 35, A199-A225 (2000)

NWA2400

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

achondrite-ung

Country

Year found

2003

Mass

136 g

[Museum Collection]

(1) 54.701g   (2) 6.418g   (3) 2.692g

This is 1 of 134 approved meteorites classified as Achondrite-ung. Published in Meteoritical Bulletin, no. 89, MAPS 40, A201-A263 (2005)

NWA13266

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

Enstatite achondrites

Country

Year found

2018

Mass

750 g

[Museum Collection]

(1) 4.53g   (2) 3.81g 

History: The meteorite was purchased from a local meteorite dealer in Niger. Physical characteristics: Dark brownish rock without fusion crust. Petrography: The meteorite is an enstatite achondrite predominantly composed of 50-1000 µm sized enstatite and less abundant sodic feldspar grains. Some regions appear to be recrystallized exhibiting triple junctions. Albitic and Si-rich glass is present throughout the meteorite. Opaque phases include nodules composed of niningerite and Cr-rich troilte, Si-rich kamacite, and rare Zn-bearing daubréelite. Metal grains are often spherical. No relict chondrules have been observed. Geochemistry: enstatite: Fs0.3±0.2Wo0.3±1.3 (Fs0.1-0.6Wo0.2-0.3, n=12); feldspar: An19.2±1.9Ab79.1±1.9Or1.7±0.2 (An81.5-92.3Ab-75.9-83.2Or1.4-2.0, n=18); kamacite: Ni=7.04±0.18, Si=2.99±0.01, Co=0.24±0.01, P=0.58±0.39 (wt%), n=3 Classification: Enstatite achondrite.

NWA13272

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

achondrite-ung

Country

Year found

2019

Mass

1603 g

[Museum Collection]

(1) 9.04g   (2) 6.05g 

History: Found in Mauritania and purchased by Rachid and Jaouad Chaoui in December 2019 from a dealer in Zouerat, Mauritania. Physical characteristics: The specimen lacks fusion crust and is coated by a shiny brown desert patina. Polished interior surfaces reveal the presence of rare tiny specks of partially altered metal. Petrography: (A. Irving, UWS and P. Carpenter, WUSL) The specimen has a fine grained, poikilitic igneous texture. Composed predominantly of polysynthetically-twinned, compositionally-zoned pyroxene oikocrysts (with domains of orthopyroxene, pigeonite and subcalcic augite) enclosing chadacrysts of olivine, together with interstitial devitrified silicic glass (pale pink in thin section) plus accessory troilite (some Cr-bearing), Ti-poor chromite and very rare kamacite (some altered to Fe hydroxides). Olivine is preferentially stained pale orange in thin section, and there are some cross-cutting dilation veins filled with comminuted olivine and orthopyroxene. Minor secondary calcite and anhydrite are present. Geochemistry: Olivine (Fa24.0-29.5, N = 8), orthopyroxene (Fs17.9-19.0Wo2.0-3.8, N = 5), pigeonite (Fs18.9-19.0Wo7.2-9.0, N = 2), subcalcic augite (Fs12.2-12.6Wo33.7-37.1, N = 4). Oxygen isotopes (K. Ziegler, UNM): analyses of acid-washed bulk subsamples by laser fluorination gave, respectively, δ17O 4.120, 4.159, 4.045; δ18O 5.908, 6.096, 5.717; Δ17O 1.001, 0.940, 1.026 per mil. Classification: Achondrite (ungrouped, igneous, with oxygen isotopic affinity to L chondrites). Specimens: 22.1 g including one polished thin section at UWB; remainder held by Mr. R. Chaoui and Mr. J. Chaoui.

NWA15061

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

Achondrite-prim-ung

Country

Year found

2022

Mass

5.72 kg

[Museum Collection]

(1) 66g

History: Reportedly found by Saharawi meteorite hunters in an area called Unan (~120 km SE of Taoudenni), Mali, in February 2022. Petrography: (K. Metzler, IfP) Achondrite with metamorphic texture, showing frequent 120° triple junctions and partly poikilitic intergrowths. It consists of olivine, low-Ca pyroxene, Ca-rich pyroxene, plagioclase, and Fe-Ni metal. Much of the latter is terrestrially oxidized, forming veins of alteration products along grain boundaries and crosscutting mineral grains. Typical grain sizes are between 200 and 500 µm, but low-Ca pyroxene grains up to several mm occur. Accessories are troilite and daubréelite. Geochemistry: Mineral compositions and geochemistry: The mean olivine composition is Fa1.2±0.1 (Fa1.0-1.4; n=9). The mean low-Ca pyroxene composition is Fs1.4±0.3Wo0.8±0.1 (Fs0.9-1.8Wo0.5-0.9; n=11). The mean composition of Ca-rich pyroxene is Fs0.9±0.3Wo40.9±0.5 (Fs0.5-1.4Wo40.3-41.6; n=10). The mean feldspar composition is An36.5±2.0Or0.1±0.1 (An32.1-38.6Or0.0-0.4; n=10). Classification: Winonaite, based on texture, mineral chemistry and high abundance of Fe-Ni metal. Specimens: 3292 g owned by Mohamed Ali Loud (largest piece 385 g). 2430 g owned by Miguel Ángel Contreras Gómez.

NWA15717

Name

*click on the Name for more information

Structure Class

achondrites

Chemical Class

Achondrite-ung

Country

Year found

2022

Mass

1000 g

[Museum Collection]

(1) 9.98 g

History: The meteorite was purchased from a meteorite dealer in Morocco. Physical characteristics: Several light grayish to cream-coloured fragments with patches of black fusion crust. Petrography: The meteorite is an achondritic breccia composed up to 2 cm sized lithic and up to 8 mm sized euhedral to subhedral mineral fragments in a fine-grained cataclastic and related matrix. Most abundant in all lithologies are Mg-rich, mostly compositionally homogeneous olivine (about 75 vol%) and low-Ca pyroxene (about 20 vol%). Zoned olivine and exsolved pyroxenes are rare. Accessories (about 5 vol%) include silica, chromite, FeS, kamacite, and taenite. Contains augite-chromite and orthopyroxene-chromite symplectites. No feldspar found. Geochemistry: compositions of individual olivine grains: Fa9.8±0.1, FeO/MnO=37±3, n=7; Fa16.7±0.1, FeO/MnO=37±1, n=7; Fa18.6±0.1, FeO/MnO=38±2, n=10; Fa20.1±0.1, FeO/MnO=41±2, n=7; Fa24.9±0.1, FeO/MnO=40±1, n=7; fayalite: Fa82.7±0.2, FeO/MnO=39±1, n=5; zoned olivine: Fa25.3±3.1 (Fa21.6-29.1, FeO/MnO=43±3, n=7); low-Ca pyroxene: Fs34.5±0.3Wo3.6±0.2, FeO/MnO=28-31, n=7); low-Ca pyroxene host to exsolution lamellae: Fs65.4±0.4Wo7.4±0.1 (Fs64.7-65.7Wo7.2-7.6, FeO/MnO=24-27, n=7); Ca-pyroxene exsolution lamellae: Fs38.5±1.8Wo38.1±2.2 (Fs37.3-41.6Wo34.3-40.0, FeO/MnO=29-34, n=7); chromite: Mg#41.5±0.8, Cr#70.2±0.2, n=7 Classification: Ungrouped achondrite, lherzolitic breccia. Likely paired with NWA 12217, NWA 12319, NWA 12562, NWA 13954, NWA 14993, and NWA 15663.

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