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EURClassification: Enstatite achondrite (Aubrite) S-high / W-low
Place/Time: 9 December 2021 in South, Morocco
Mass: 2.22kg
Physical characteristics: Six large pieces and many small fragments were recovered. The main mass is a 736 g complete stone, the other large pieces include: 507 g (broken), 310 g (complete), 209 g (complete), 130 g (broken), and 40 g (broken). Exterior is covered with multi-colored (green-orange-brown) fusion crust. Broken surfaces reveal a mild breccia of mm- to cm-sized fractured bright white pyroxene grains, elongate to stubby, permeated and bounded by shock-darken domains. Large pyroxenes include black material as needles or grain inclusions. Samples are fragile and easily broken. Magnetic susceptibility, measured on different stones, ranges from log χ (× 10-9 m3/kg) = 2.7 to log χ (× 10-9 m3/kg) = 3.6 (H. Chennaoui Aoudjehane, FSAC).
Petrography: (A. Ross and C. Agee, UNM) Backscatter electron image maps show that enstatite makes up ~90-95% of this meteorite. Scattered diopside and olivine grains were observed, and only a single albite grain was detected in the microprobe mount. A few aluminous silica polymorph grains were also found. Ubiquitous shock melt pockets and veinlets are present throughout, most of which are silica-rich or albitic, although some are diopsidic in composition, and some have minor amounts of sulfur. Detected sulfides include: troilite, Ti-troilite, Cr-troilite, Mn-troilite, ferroan alabandite, ferromagnesian alabandite, daubreelite, and oldhamite. Metals include kamacite and taenite; Si was below detection limits in both metals. Rare schreibersite was observed. Vesicular enstatitic fusion crust was observed by BSE, apparent thickness is ~100-300 μm.
NOTE: Crazy oriented specimen witn bubbled crust. Only two broken sides, rest of specimen is complete with round front surface and back milky sponge crust. This one look near identical to Ribbeck.
