(Lodranite, minimal weathering) Meteoritical Bulletin #99
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Northwest Africa 6592 (NWA 6592)
(Northwest Africa)
Purchased: May 2007
Classification: Primitive achondrite (Lodranite)
History: A single stone was bought in May 2007 from a nomad who had found it in the Hamada du Guir area across the Moroccan-Algerian border.
Physical characteristics: A single oriented stone covered with fresh fusion crust showing flow lines.
Petrography: (J. Gattacceca, CEREGE): Coarse-grained (1 to 2 mm) mineral aggregate with triple junctions. Modal abundances: olivine 63.6%, orthopyroxene 14.0%, kamacite 11.2%, clinopyroxene 5.6%, feldspar 3.6%, chromite 1.4%, Ca phosphate 0.4%, troilite 0.2%. Magnetic susceptibility log χ = 5.70 (χ in 10-9 m3/kg).
Geochemistry: (J. Gattacceca, CEREGE) Olivine Fa13.9. Orthopyroxene Fs13.1Wo2.9. Clinopyroxene Fs7.2Wo36.6 containing 1.3% Cr2O3. Chromite Cr/(Cr+Al) = 0.85. Oxygen isotopes of a 1.5 mg olivine sample (C. Suavet, C. Sonzogni, CEREGE): δ17O = 1.04 ‰, δ18O = 3.98 ‰, and Δ17O = -1.03 ‰.
Classification: Achondrite (lodranite). Minimal weathering.
Specimens: CEREGE holds 3.2 g distributed between a slice and a polished section. P. Thomas holds the main mass.
| Origin or pseudonym: | Hamada du Guir |
| Date: | P May 2007 |
| Mass (g): | 15.85 |
| Pieces: | 1 |
| Class: | Lodranite |
| Weathering grade: | W1 |
| Fayalite (mol%): | 13.9 |
| Ferrosilite (mol%): | 7.2 |
| Wollastonite (mol%): | 36.6 |
| Magnetic suscept.: | 5.70 |
| Classifier: | J. Gattacceca |
| Type spec mass (g): | 3.2 |
| Type spec location: | CEREGE |
| Main mass: | P. Thomas |
| Comments: | Submitted by J. Gattacceca |
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