Northwest Africa 15576 (NWA 15576)

(Northwest Africa)

Find: 2022

Classification: Enstatite chondrite (EL6)

History: Single stone purchased by Nicola Castellano at the Genova Mineral Fair in 2022 and weighing 248 g

Physical characteristics: Main mass without fusion crust. A cut surface displays several metal veins in a brown silicate equilibrated matrix.

Petrography: (V. Moggi Cecchi, G. Pratesi, L. Fabrizi, UniFi): An equilibrated texture consisting of a fine-grained, pyroxene-rich matrix, with minor plagioclase and no relic chondrules is visible in thin section. Kamacite and troilite, partially weathered to iron oxides, are the main opaque phases. Troilite occasionally displays blades of daubréelite and rare alabandite. 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_0.6±0.1En_98.0±0.3Wo_1.4±0.1), plagioclase (An_15.3Or_4.1); Si in kamacite = 0.6 wt.%, Mn in daubréelite = 2.7 wt.%

Classification: Enstatite Chondrite (EL6); S2; W2;

Specimens: The main mass, weighing 248 g, is owned by Castellano; the type specimen, weighing 28.1 g , and one thin section are on deposit at MSN-FI (Inventory # I-3703).