CR
Name
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Structure Class
Carbonaceous chondrites
Chemical Class
CR2
Country
Year found
2006
Mass
76 g
[Museum Collection]
(1) 7.8g
This is 1 of 187 approved meteorites classified as CR2. Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008)
Name
*click on the Name for more information
Structure Class
Carbonaceous chondrites
Chemical Class
CR2
Country
Year found
2001
Mass
5 kg
[Museum Collection]
(1) 97.1g
History: M. Farmer and G. Hupe recovered a total of approximately 5 kg of many individuals and fragments from Zagora, Morocco. Many whole and sliced specimens have been sold over the last several years. Physical characteristics: Many whole stones and fragments, all with desert varnish and brown/orange color. Numerous chondrules, many on the order of ~ 1 mm in apparent diameter, are visible. Petrography: (G. Benedix and C. Smith, NHM) The thin section studied is dominated by millimeter-sized Type I PO and POP chondrules, which are often rimmed with and/or contain metallic Fe-Ni blebs. Metallic Fe-Ni also occurs as rounded, millimeter-sized grains within the matrix. Interstitial to chondrules and metal is a fine-grained matrix rich in phyllosilicate.Two Type II chondrules were also observed. Pervasive veins of rust occur throughout. Mineral compositions: Type 1 chondrule olivine (Fo98.2±1.3), low-Ca pyroxene (En96.2±0.9Wo2.0±2.2), high-Ca pyroxene(En45.7±11.5 Wo35.9±4.7). Type II chondrule olivine (Fo77.4±7.7), low-Ca pyroxene (En73.8±1.8Wo2.1±2.4). Classification: Carbonaceous chondrite (CR2); moderate to extensive weathering. Type specimens: A total of 77.4 g of sample and two sections are on deposit at NHM. MFarmer holds several grams, KCCU holds approximately 10 g, AMNH hold several grams.
Name
*click on the Name for more information
Structure Class
Carbonaceous chondrites
Chemical Class
CR2
Country
Year found
2009
Mass
775 g
[Museum Collection]
(1) 41.7g (2) 6.1g (3) 4.9g (4) 4.6g
(5) 4.42g (6) 4.41g (7) 4.11g (8) 4.0g
(9) 3.4g (10) 2.6g (11) 2.4g (12)0.7g
History: Purchased by Twelker in 2011 August from a dealer in Erfoud, Morocco. Petrography: (A. Irving and S. Kuehner, UWS) Well-formed medium-sized (0.3 to 0.7 mm) chondrules in a dark-brown, fine-grained matrix containing hydrous minerals (including cronstedtite), Ni-bearing sulfides and rare chlorapatite. Olivine, orthopyroxene, pigeonite, augite, chromite and troilite. Geochemistry: Olivine (Fa1.5-51.5; Cr2O3 in ferroan olivine 0.06-0.38 wt.%, mean 0.20 wt.%, s.d. 0.13 wt.%, N = 8), orthopyroxene (Fs2.6Wo0.3), pigeonite (Fs27.3Wo14.5), augite (Fs15.2Wo45.6). Oxygen isotopes (R. Tanaka, OkaU): analyses of acid-washed subsamples by laser fluorination gave δ17O = 0.33, 0.84; δ18O = 4.12, 4.74; Δ17O = -1.844, -1.652 per mil Classification: Carbonaceous chondrite (CR2).
Name
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Structure Class
Carbonaceous chondrites
Chemical Class
CR6
Country
Year found
2012
Mass
1096 g
[Museum Collection]
(1) 8.63g (2) 0.83g
History: Purchased by Marcin Cimała and Tomek Jakubowski from two separate dealers in Erfoud and Zagora in 2012 April and June. Physical characteristics: Four fresh, pale greenish stones (122 g, 151 g, 187 g, 636 g), all partially coated with black fusion crust. Petrography: (A. Irving and S. Kuehner, UWS) Overall poikiloblastic texture, but there are rare BO chondrules with annular olivine rims. Minerals present include olivine (some as larger grains), orthopyroxene, minor clinopyroxene, intermediate plagioclase, fresh kamacite, chromite, troilite, and merrillite. Geochemistry: Olivine (Fa38.0-38.2, FeO/MnO = 72-79), orthopyroxene (Fs29.3-29.4Wo3.3-3.0, FeO/MnO = 53-61), clinopyroxene (Fs12.8-14.2Wo42.7-40.5, FeO/MnO = 40-41). Oxygen isotopes (R. Tanaka, OkaU): analyses of acid-washed subsamples by laser fluorination gave δ17O = 0.057, 0.064; δ18O = 3.507, 3.594; Δ17O = -1.788, -1.827 per mil. Classification: Carbonaceous chondrite (CR6). This specimen is a highly equilibrated CR chondrite paired with NWA 2994, NWA 3250, NWA 6901 and NWA 6921. Specimens: A total of 22 g of sample and one polished thin section are on deposit at UWB. Mr. M. Cimała and Mr. T. Jakubowski jointly hold the main masses.