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Northwest Africa 4255
Basic information Name: Northwest Africa 4255
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4255
Observed fall: No
Year found: 2002
Country: Algeria
Mass:help 6 kg
Meteoritical Bulletin:  MB 92  (2007)  Diogenite
Recommended:  Diogenite    [explanation]

This is 1 of 481 approved meteorites classified as Diogenite.   [show all]
Search for other: Achondrites, Diogenites, and HED achondrites
Comments: Approved 24 Jul 2007
Writeup from MB 92:

Northwest Africa 4255                 27°51'00"N, 7°48'00"W

Hamada du Draa, southwest of Algeria

Find: September 2002

Achondrite (diogenite)

History: Nomads found the meteorite in September 2002 in Hamada du Draa, Southwest Algeria.

Physical characteristics:The total mass is 6000 g and is fragmented into 100s of pieces, some of which are partly covered with fusion crust.

Petrography: (A. Seddiki, Ud'OEA and UJM; B. Moine, J.Y. Cottin, UJM; M. Denise, V. Sautter, J.P. Lorand, MNHNP). Predominantly composed orthopyroxene with scarce inclusions of troilite, ilmenite, spinel, olivine and metallic Fe-Ni.

Mineral compositions and geochemistry: Orthopyroxene (Fs25.3Wo1.5; Fe/Mn = 23-28 [atomic]), spinel (Cr = 0.92 wt%), olivine (Fa30), Fe, Ni-rich metal (NiO = <1 wt%). Oxygen isotopes: δ18O = 3.25, δ17O = 1.31, Δ17O = -0.38 (all ‰).

Classification: Achondrite (diogenite); S2, minor weathering.

Type specimens: A total of 21 g of sample is on deposit at MNHNP. Two thin sections are on deposit at UJM. An anonymous finder holds the main mass.

Data from:
  Table 2
  Line 18:
Place of purchase:Hamada du Draa
Mass (g):6000
Pieces:Many 100s
Type spec mass (g):21
Plots: O isotopes:  
   and collections
MNHNP: Museum National d'Histoire Naturelle, IMPMC-CP52, 57 rue Cuvier, 75005 Paris, France, France; Website (institutional address)
UJM: Université Jean Monnet, Saint-Etienne, France (institutional address)
References: Published in Meteoritical Bulletin, no. 92, MAPS 42, 1647-1694 (2007)
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     Recommended::   (27° 51'N, 7° 48'W)

     This is 1 of 45 approved meteorites from Tindouf, Algeria (plus 1 impact crater)
     This is 1 of 1156 approved meteorites from Algeria (plus 27 unapproved names) (plus 4 impact craters)
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