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NWA 7821

C2-ung or CM2-an
standby for nwa 7821 photo
Purchased 2012
Eight fragments of a single meteorite having a combined weight of 38 g were found in the desert region of Northwest Africa. The pieces were sold at the 2013 Tucson Gem and Mineral Show to G. Hupé. A type sample was submitted for analyses and classification to the University of Washington at Seattle (A. Irving and S. Kuehner), and NWA 7821 was determined to be a new ungrouped C2 chondrite, or alternatively, an anomalous member of the CM chondrite group.

Northwest Africa 7821 is a low-density carbonaceous chondrite containing scattered granular chondrules ranging in size from 0.1 to 0.4 mm. CAIs are present in a fine-grained matrix having a composition similar to that of CM chondrites. The meteorite has been shocked to S2 and terrestrially weathered to a grade of W2. On an oxygen three-isotope diagram, NWA 7821 plots along the CM trend line for CM chondrites but with a higher than normal 16O content (Carnegie Institution, Washington D.C. (D. Rumble, III; see O-isotopic diagram). The specimen of NWA 7821 shown above is a 0.056 g partial slice. The photo shown below is one of the larger slices photographed by G. Hupé.

standby for nwa 7821 photo
Photo courtesy of Greg Hupé—Nature’s Vault

This content is reposted with permission from David Weir under an evergreen, exclusive worldwide license.

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