Macroscopic Description: Roy S. Clarke, Jr.

This oval-shaped button was oriented during atmospheric passage, resulting in a domed anterior surface with a flat posterior. A thin film of reddish brown to black secondary oxides covers the specimen. There is a suggestion of an accumulation of material at the rim where the two surface types join, but fusion crust is not apparent. The internal Widmanstatten pattern stands out in relief on the anterior surface, while the posterior surface is matted terrestrial oxides.

Polished Section Description: Roy S. Clarke, Jr.

A median slice perpendicular to both the long axis of the oval and to the flat posterior surface was removed, producing butts of 27.5 g and 20.7 g, and a 3.1 mm slice of 7.7 g from which a metallographic section was prepared. Fusion crust is absent on the anterior surface, but an accumulation of columnar fusion crust is present at both ends of the posterior surface. They are ~1 mm thick near the rim where the surfaces join, and taper to nothing in ~9 mm. Heat alteration as indicated by ₂ structure affects all but the most interior parts of the section. The plane of section is parallel to the 100 direction of the parent taenite, resulting in a Widmanstatten pattern of kamacite bands in two orthogonal directions with widths of approximately 1.5 mm. The structure, although heat-altered, is regular and otherwise undistorted. It contains several of the more common taenite-plessite structures. Neumann bands are present in the α₂-free kamacite. Rhabdites are present within kamacite, and grain-boundary schreibersites and taenite-border schreibersites are present. Troilite was not observed but is probably present. Both GRO95511 and GRO95522 are similar in appearance and weathering history. Their Widmanstatten patterns are revealed on different planes, and they have different exposures to preterrestrial distortion and heating. This makes it difficult to suggest if they represent two separate falls or are individuals from a shower. Definitive classification and pairing information awaits trace element analysis.