Sample No.: PAT91528

Location: Patuxent Range

Dimensions (cm): 1.5 x 1.3 x 0.6

Weight (g): 3.3

Meteorite Type: Iron nodule with minor silicates?

Macroscopic Description: Roy S. Clarke, Jr,

The specimen is mildly weathered with no obvious fusion crust remaining. Looking down on it sitting on its comparatively large flat surface, its shape is reminiscent of a fluffed out bird sitting on a nest. The thickest point is its "head", and on the bottom surface at the opposite end from the "head' is a small protrusion pointing down, a "tail".

Polished Section Description: Roy S. Clarke. Jr,

A median slice was removed perpendicular to the flat surface and through the "head and tail." Butts of 1.9 g and 0.7 g resulted. A metallographic section of 35 mm2 resulted. The section contains one large untwinned troilite (2 mm2), the "tail" of the bird. The remainder of the section, essentially a right triangle in outline, is rimmed with -500 μm of reasonably clear metal containing few small inclusions. This rim borders another ~500 μm zone that is richer in tiny inclusions. Interior to this is a uniform martensite structure. Diagonally across from the large sulfide, at the "head" of the bird, are two silicate areas of ~0.5 mm2, partially bordered by schreibersite. A small number of microprobe analyses average Fa26 and Fa23. Fa values vary from Fa22 to Fa29, and Fs values from Fs22 to Fs25. An electron microprobe traverse into the metal reveals a Ni gradient in the first 1 mm from the outside edge from 40 wt% down to ~20 wt%. The interior of the grain has irregular Ni values averaging around 15 wt%. During this part of the traverse occasional small schreibersites gave very high Ni values and occasional small kamacites gave values around 5 wt%. This specimen is a metal nodule from a more complex meteorite. The Fa and Fs values suggest the possibility of an L chondrite association, but the P content of the metal argues against it. Although no silicate has been seen in PAT91516, there are many metallographic similarities. Could these be from the same parent?