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Northwest Africa 4425
Basic information Name: Northwest Africa 4425
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4425
Observed fall: No
Year found: 2006
Country: Algeria
Mass:help 579 g
Meteoritical Bulletin:  MB 93  (2008)  CK3
Recommended:  CK3    [explanation]

This is 1 of 79 approved meteorites classified as CK3.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), CK chondrites, CK3 chondrites, and CV-CK clan chondrites
Comments: Approved 17 Apr 2008
Revised 4 Aug 2008: final writeup
Writeup from MB 93:

Northwest Africa 4425


Find: May 2006

Carbonaceous chondrite (CK3)

History: A stone was purchased by P. Thomas in May 2006.

Physical characteristics: A complete, ventifacted stone weighing 579 g, without fusion crust. It has a brownish color indicating significant terrestrial alteration.

Petrography: (M. Bourot-Denise, MNHN) Chondrules are mm-sized. Most CAIs are also visible to the naked eye. The type specimen contains a CAI 1.5 cm in diameter rimmed with spinel and diopside. Chondrules are generally porphyritic with wide rims, and contain magnetite beads. Large opaque nodules of magnetite and sulfide are present in the matrix. Matrix is either crystallized or fine, with abundant small magnetite crystals. BSE images indicate that this chondrite is not completely equilibrated; olivines and pyroxene in porphyritic chondrules are zoned. In the type specimen, there is an angular clast, 2 cm in diameter, containing small, porphyritic pyroxene chondrules (100- 500 µm); chondrules and well-crystallized matrix are completely equilibrated; magnetite is finely scattered through the clast and does not make up nodules as in the host; the interface between the clast and the host is highlighted by small, euhedral magnetites.

Geochemistry: Olivine (Fa13.6±12.6; range Fa0.54-34.1), low-Ca pyroxene (Fs16.8±11.0; range Fs2.8-30.7), magnetite (Cr2O3 = 2.6-3.7, MgO = 0.87-1.15 [both wt%]) all in the CK3 domain. Pyroxene in the angular clast: Fs23.35±0.86. Magnetic susceptibility (J. Gattacceca, CEREGE) log χ = 4.6 10-9 m3/kg.

Classification: Carbonaceous chondrite (CK3, estimated subtype 3.8); minimal shock and moderate weathering.

Type specimens: A total of 32.8 g of sample (1 sawn fragment) and two polished mounts are on deposit at MNHN. Thomas holds the main mass.

Submitted by: M. Bourot-Denise, MNHN.

Data from:
  Table 2
  Line 46:
Place of purchase:Algeria
   and collections
CEREGE: CEREGE BP 80 Avenue Philibert, Technopole de l'Arbois 13545 Aix-en-Provence Cedex 4 France, France (institutional address; updated 10 Jun 2023)
MNHN: Museum National d'Histoire Naturelle, IMPMC-CP52, 57 rue Cuvier, 75005 Paris, France, France; Website (institutional address)
References: Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008)
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Photos from the Encyclopedia of Meteorites:
Don Edwards   


     This is 1 of 1315 approved meteorites from Algeria (plus 30 unapproved names) (plus 4 impact craters)

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