Northwest Africa 15571 (NWA 15571)

(Northwest Africa)

Find: 2018

Classification: Enstatite chondrite (EL5)

History: A single stone weighing 199 g was purchased by Romano Serra at Erfoud in 2018

Physical characteristics: The main mass displays no fusion crust. A cut surface reveals several black veins and a markedly altered brown matrix.

Petrography: (V. Moggi Cecchi, G. Pratesi, L. Fabrizi, UniFi): An equilibrated chondritic texture consisting in a fine-grained, pyroxene-dominant matrix, with minor plagioclase and few relict chondrules visible in the thin section. Metal veins are diffuse. Kamacite and troilite, partially weathered to iron oxides are the main opaque phases. Daubréelite and minor alabandite are occasionally visible in troilite. The presence of alabandite, An content of plagioclase and Si content of kamacite point to a classification as EL chondrite.

Geochemistry: EMP (V. Moggi Cecchi, G. Pratesi, L. Fabrizi, UniFi): Orthopyroxene (Fs_0.4±0.1En_98.2±0.3Wo_1.4±0.1), plagioclase (An_15.5Or_4.2); Si in kamacite = 0.6 wt.%, Mn in daubreelite = 2.6 wt.%

Classification: Enstatite Chondrite (EL5); S2; W2;

Specimens: The main mass, weighing 176 g, is on deposit at OAM; the type specimen, weighing 32.1 g, and one thin section are on deposit at MSN-FI (Inventory # I-3689).