Northwest Africa 16273 (NWA 16273)

Morocco (Erfoud)

Find: 2010

Classification: Mesosiderite

History: The meteorite was purchased in Erfoud rock market in 2010 (Morrocco).

Physical characteristics: One dark-brownish fragment without fusion crust. The sawn surfaces show a mixture of silicate phases and metal.

Petrography: (R.Kared, UO-MBA, L. Riguet and B. Moine, LMV, and A. Seddiki, UO-MBA) Microscopically the meteorite is composed of silicate (about 50%) and fresh metal. The silicate fraction is dominantly composed of mm- to cm-sized olivine clasts, compositionally zoned low-Ca pyroxene and plagioclase. Minor phases are chromite, phosphate, rutile, ilmenite and rare sulfide (FeS). The metallic lithology consists of taenite and kamacite that include few schreibersite crystals.

Geochemistry: Mineral compositions and geochemistry: (R. Kared, UO-MBA, L. Riguet and B. Moine, LMV, and A. Seddiki, UO-MBA) Major and minor element chemistry of mineral phases was determined using an electron microprobe at LMV. Electron microprobe analyses showed: olivine compositions of Fa_{28.6 ± 7.5} (n=20); pyroxenes compositions of Fs_{28.1 ±4.7} Wo_{5.4 ± 4.1} with Fe/Mn = 27.8 ± 3.1 (n=24). The plagioclases are mainly bytownites and anorthites An_{90.6 ± 1.4} Or_{0.4 ± 0.1} (n=11). The compositions of plagioclase varie from An_87-92 Or _0.2-0.6. Chromite Cr# varie from 66.7 to 77.9 (100*Cr/(Cr+Al)). Chromite Cr# 72.5±8.4 (100*Cr/(Cr+Al), n=7). Fe-metal: Taenite 39.7 ± 6.3 wt% Ni (n=12), Kamacite 5.8±0.6wt% Ni, (n=15).

Classification: Stony-Iron Meteorite (Mesosiderite)

Specimens: mass: 54 g; 12.1 g deposited at MNHNP.