Meteorite collection 18 May 2022

NWA 6685 (Sahara) – Lodranite

probably paired


Northwest Africa 6685 (NWA 6685)

(Northwest Africa)

Purchased: 2010

Classification: Primitive achondrite (Lodranite)

History: Purchased by Giorgio Tomelleri from a dealer in Erfoud, Morocco.

Physical characteristics: A complete stone weighing 524 g, with fusion crust.

Petrography: (V. Moggi Cecchi, G. Pratesi, S. Caporali MSP). The thin section is dominated by large olivine and subordinate orthopyroxene phenocrysts (to 8 mm) embedded in an interstitial fine-grained matrix of the same phases. The matrix grains range from 0.01 to 0.1 mm. Plagioclase is absent. Opaques consist of kamacite and troilite, frequently altered to iron oxides.

Geochemistry: Orthopyroxene, Fs10.7, Fe/Mn=14; olivine, Fa10.8, Fe/Mn=23; Ca-pyroxene, Fs3.4En52Wo44.6; Cr in troilite=0.60 wt%; Oxygen isotopes (I.Franchi, R.Greenwood, OU): δ17O = 0.10; δ18O = 2.50; Δ17O = -1.2 per mil.

Classification: Achondrite (lodranite). Highly weathered. Moderately shock.

Specimens: 23.4 g is on deposit at MSP (MSP 5151).

You may also like...