![]() |
||
|
Northwest Africa 7821 | |||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Basic information | Name: Northwest Africa 7821 This is an OFFICIAL meteorite name. Abbreviation: NWA 7821 Observed fall: No Year found: 2013 Country: (Northwest Africa) Mass: ![]() | ||||||||||||||||||||||||||||||
Classification history: |
This is 1 of 25 approved meteorites classified as C2-ung. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), and Ungrouped chondrites | ||||||||||||||||||||||||||||||
Comments: | Approved 18 Nov 2013 | ||||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 102:
Northwest Africa 7821 (NWA 7821) (Northwest Africa) Purchased: 2013 Feb Classification: Carbonaceous chondrite (C2, ungrouped) History: Purchased by GHupé in February 2013 from a dealer at the Tucson Gem and Mineral Show. Petrography: (A. Irving and S. Kuehner, UWS) Very soft, fine grained specimen consisting of sparse tiny (0.1-0.4 mm), granular chondrules, mineral fragments and rimmed, amoeboid CAI in a brown, fine-grained matrix with possible cronstedtite and tochilinite. Some chondrules exhibit replacement by phyllosilicates. Anhydrous minerals include olivine, orthopyroxene, clinopyroxene, minor fresh kamacite and pentlandite. Geochemistry: Olivine (Fa0.7-41.9), orthopyroxene (Fs0.6-32.3Wo3.7-2.8), clinopyroxene (Fs0.5Wo33.0). Oxygen isotopes (D. Rumble, CIW): analyses of acid-washed subsamples gave, respectively δ17O -2.98, -3.37; δ18O 0.95, 0.38; Δ17O -3.483, -3.574 per mil. Classification: Carbonaceous chondrite (CM2-an). Oxygen isotopes do not plot with the values for other CM chondrites, but on an extension of that trend towards more 16O-rich compositions, making this specimen anomalous. Specimens: 7.6 g and one polished thin section are at UWB. The remainder is held by GHupé. | ||||||||||||||||||||||||||||||
Data from: MB102 Table 0 Line 0: |
|
||||||||||||||||||||||||||||||
Plots: | O isotopes: | ||||||||||||||||||||||||||||||
Institutions and collections |
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012) UWB: University of Washington, Burke Museum of Natural History and Culture, Box 353010 Seattle, WA 98195, United States (institutional address; updated 9 Oct 2023) CIW: Carnegie Insitution Washington, Geophysical Laboratory, 5251 Broad Branch Rd., NW, Washington DC 20015, United States (institutional address) GHupé: Gregory M. Hupé, 9003 Placid Lakes Blvd., Lake Placid, FL 33852, United States; Website (private address) Hupe: (old address—now see GHupé or AHupé) G. and A. Hupe, 2616 Lake Youngs Court SE, Renton, WA 98058., United States (private address) |
||||||||||||||||||||||||||||||
Catalogs: |
| ||||||||||||||||||||||||||||||
References: | Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
| ||||||||||||||||||||||||||||||
Geography: |
Statistics: This is 1 of 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names) |