3.16g CHERGACH Crusted Oriented Meteorite I Witnessed Fall
On Offer: 3.16g Chergach crusted oriented meteorite Name: Chergach Type: Ordinary Chondrite H5 Observed fall: Yes Description: Oriented crusted fresh individual Chergach H5. This chondrite was witnessed to fall in Mali in 2007. What you get: 3.16 gram Chergach oriented individual as shown, Membrane Storage/Display Box, & signed Certificate of Authenticity. I offer a 100% no questions asked 30 day return policy. SEE OFFICIAL METEORITICAL SOCIETY ENTRY BELOW Chergach Basic information Name: Chergach This is an OFFICIAL meteorite name. Abbreviation: There is no official abbreviation for this meteorite. Observed fall: Yes Year fell: 2007 Country: Mali Mass: 100 kg Classification history: Meteoritical Bulletin: MB 94 (2008) H5 Recommended: H5 [explanation] This is 1 of 10273 approved meteorites (plus 18 unapproved names) classified as H5. [show all] Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7) Comments: Approved 4 May 2008 Writeup Writeup from MB 94: Chergach 23° 41’47’’N, 5° 00’53’W SW El Mokhtar, Erg Chech, Timbuktu district, Mali Fall: 2 or 3 July 2007, daytime Ordinary chondrite (H5) History: In fall and winter, 2007 ~100 kg of meteorites were collected in the Erg Chech, north of Taoudenni. Nomads reported the stones fell after a smoke cloud was seen and several detonations were heard over a wide area during daytime in July 2007. The finder of the first meteorites was Mr Ouled Bleila, who died in a car accident on his way back from the trip to the Chergach strewn field in October 2007. According to the Tuareg people from Algeria who visited the fall site in September 2007, the elliptical strewn field stretches for more than 20 km in a northeasterly direction. No fireball was reported. Physical characteristics: A large number of fusion-crusted stones have been recovered, the largest ones are 17.8 and 13.9 kg, the smallest ones about 1.5 g. Total known weight ~100 kg. Petrography: (E. Gnos, MHNGE; B. Hofmann, NMBE, M. Eggimann, UBE/NMBE) Mean chondrule size is 0.38 mm (n = 61). Mean size of plagioclase grains is ~20 μm. Troilite is polycrystalline, rich in silicate inclusions, and shows diffuse boundaries to metal. Some metal is rich in silicate- and troilite inclusions. No Cu metal observed. Shock stage is S3, some shock veins are visible, no weathering (W0). In addition to this dominant lithology, a significant number of stones consist of chondritic clasts (H5 S3-4 W0, identical to the homogeneous lithology) set in a fine-grained, black, silicate impact melt matrix with abundant droplets of metal and metal-troilite. Shock stage of small clasts is up to S4. Mineral compositions and geochemistry: Olivine Fa18.2 (chondrite fragments in impact melt are Fa18.4), pyroxene Fs15.5 Wo1.2 (fragments in impact melt are Fs16.0, Wo1.4). Cosmogenic radionuclides: (Patrick Weber, Particle Physics Group, Institute of Physics, University of Neuchâtel) Gamma-spectroscopy performed in November, 2007 showed the presence of the following short-lived radionuclides: 46Sc, 56Co, 54Mn, 58Co, 7Be, 57Co, 22Na, 60Co, 26Al. Recalculated to July, 2007, 22Na was 44.0 ± 1.1 dpm/kg and 26Al 20.8 ± 0.8 dpm/kg. The 22Na/26Al activity ratio of 2.1 is consistent with a fall in July, 2007 and demonstrates that this material is not identical with Bassikounou. Classification: Ordinary chondrite (H5), some stones suggest an H impact melt breccia. S3, W0. Type specimens and distribution: 115 g at NMBE; 17.8 kg P. Hermann, Canada; 13.9 kg D. Gheesling, USA; 4.9 kg S. Buhl, Germany. Data from: MB94 Table 1 Line 3: State/Prov/County: Timbouctou district, Mali Date: 2-Jul-07 Latitude: 23°41'47"N Longitude: 5°00'53'W Mass (g): 100000 Pieces: Many Class: H5 Shock stage: S3 Weathering grade: W0 Fayalite (mol%): 18.2 Ferrosilite (mol%): 15.5 Wollastonite (mol%): 1.4 Classifier: Type spec mass (g): 115 Type spec location: NMBE, E. Gnos, MHNGE; B. Hofmann, NMBE, M. Eggimann, UBE/NMBE Main mass: Dgheesling