Erg Chech 012 (EC 012)        26º13.5425’N , 01º45.6455’W

Adrar, Algeria

Purchased: 2022

Classification: Martian meteorite (Shergottite)

History: The meteorite was found by a nomad and purchased by Carlos Muñecas Muñoz (Expometeoritos) from a dealer in Morocco in June of 2022.

Physical characteristics: Sample is irregularly shaped and lacks fusion crust. The cut face shows the interior is light greenish- gray and crystalline.

Petrography: Description and classification (A. Love, App) Sample has a diabasic texture composed of (vol%): 1-2 mm sized twinned, prismatic pyroxenes (60); lath-shaped regions of maskelynite (35), some of which are surrounded by later stage K-bearing glass. Pyroxenes are strongly zoned (cores show thin exsolution lamellae). Additional minerals are: fayalitic olivine (Fa₉₁), a silica polymorph, calcite, merrillite, Cl-apatite, ulvospinel, ilmenite and pyrrhotite.

Geochemistry: (A.Patchen, UTK) Pigeonite cores (Fs_33.2±2.2Wo_11.8±1.4, Mg#62.3±2.3, Fe/Mn=29.7±0.9, n=12); augite cores (Fs_23.6±1.8Wo_33.4±1.6, Mg#64.6±2.2, Fe/Mn=28.8±1.6, n=31); pigeonite rims (Fs_62.8±5.3Wo_15.3±2.0, Mg#25.7±6.8, Fe/Mn=37.7±1.1, n=53); augite rims (Fs_60.9±7.0Wo_21.3±4.6, Mg#=22.6±7.3, Fe/Mn=37.8±1.9, n=52); maskelynite (An_56.0±2.4Or_1.4±0.5, n=13); non-stoichiometric anorthoclase (Ab_37.1Or_27.0); Ti-magnetite (Sp_4.2±0.8Chr_1.2±0.9Usp_69.1±2.5Mt_25.5±2.5, Mg#=0.9±0.5, n=58); ilmenite (Ilm_95.2±0.8Hem_1.9±1.0, n=40); fayalite(Fa_91.1±2.2, Fe/Mn=52.1±2.5, n=24).

Classification: Martian achondrite (basaltic shergottite). Based on texture, unequilibrated mineralogy, Fe/Mn ratio measured from pyroxenes, sample is a basaltic shergottite.

Specimens: Carlos Muñecas Muñoz (Expometeoritos) holds the main mass. A polished thin section and an endcut and slice weighing a total of 5 g are on deposit at App.