Sample No.: EET84300

Location: Elephant Moraine

Weight (g): 72.2

Field No.: 2489

Dimensions (cm): 3.5 x 3 x 2

Meteorite Type: Silicate-rich finest Octahedrite

Macroscopic Description: Roy S. Clarke, Jr.

This specimen is irregularly shaped, pitted, weathered, and covered with a reddish brown coating of secondary oxides.

Polished Section Description: Roy S. Clarke, Jr.

An off-center section through the specimen provided an area of 4 sq. cm for examination. About one-third of this surface area contains silicate clusters and individual silicate crystals dispersed in metal. These Orsilicate [sic] association comprise about 5% of the total area. The metal is polycrystalline, containing three cm-size areas of finest octahedrite structure with band widths around 0.1 mm. These three large areas are separated by two comparatively wide bands of kamacite containing median grain boundary schreibersite. The silicate-rich area is more complex and contains smaller areas of finest octahedrite structure. The slice is rimmed with essentially continuous secondary oxides about 0.2 mm thick. A few small metal areas near the rim contain «2 structure, its deepest penetration being less than 0.5 mm.

Dominant features within the metal areas are a Widmanstätten pattern of taenite, cellular plessite, and kamacite lamellae. Schreibersite is found at junctions of kamacite lamellae, at centers of kamacite lamellae, and within plessite areas. A number of graphite inclusions are present, ranging in size from a few hundredths of a mm to 0.5 mm. Tiny inclusions of daubreelite were tentatively identified.

Silicates occur as clusters and as individual grains within metal. They range from transparent to translucent, and from water-clear to slightly colored. Some of the coloring is probably due to weathering. A 0.5 mm transparent and slightly green crystal proved on electron microprobe examination to be diopside. Other silicates identified were plagioclase (An12), olivine (Fa0.8), and pyroxene (Fs6). The cluster silicates are coarsely crystalline, and associated with polycrystalline troilite, small amounts of metal, and schreibersite and/or carbide.

This specimen is a silicate- and graphite-rich polycrystalline finest octahedrite. It is distinct from EET83333.