Sample No.: LEW86211; 86498

Location: Lewis Cliff

Weight (g): 163.1; 134.2

Field No.: 2317; 4894

Dimensions (cm): 4.5x4x3; 5x3x3

Meteorite Type: Anomalous Iron

Macroscopic Description: Roy S. Clarke, Jr.

A 72.6 gram specimen (LEW86211,3), 4.1 x 2.9 x 2.8 cm, was broken from a larger mass during processing, resulting in approximately two-thirds of its surface area being original exterior and the remainder being interior. The exterior surface is weathered fusion crust, predominately reddish brown in color, containing occasional patches of retained black fusion crust. There are areas of iridescent coloring, and while smooth to the touch, the surface has an unusual roughness and angularity of appearance when viewed with low magnification. There are occasional very small areas (0.1 to 0.5 mm) of bronze colored material. The broken surface areas have a hackly appearance and a predominately yellow color that varies from pale brass yellow to bronze yellow. Under magnification (20x) the yellow material is seen to be present as globules, as fracture surfaces and crystal faces, and as fine filaments. A few small areas appear to be vugs coated with a drusy material. Whether these vug fillings are indigenous or a weathering phenomenon is not clear. A few very small areas of silicates appear to be present as is an occasional chromite.

Polished Section Description: Roy S. Clarke. Jr. and René Martinez

This cursory description is based on the examination of a 1 cm² section, and of a slice of 6 cm² removed from the piece described above. These reveal a matrix of coarsely crystalline troilite containing globular metal. Metal and troilite are in roughly equal proportions. A typical metal area is 0.3 x 0.6 mm, although particles larger or much smaller are also present. Troilite crystals are in the mm size range and are cracked on the 1/10 mm range. Weathering has penetrated along some of these cracks and along metal/troilite interfaces. A martensitic pattern develops in the metal on etching. Centers of these areas contain 8-9% Ni, while edges contain as much as 20% Ni. There are also occasional silicate-rich areas present. The silicates are fine-grained, the areas are vesicular, and weathering has penetrated into these areas. LEW86498 was broken exposing a fine-grained, vesicular silicate inclusion about 1.5 x 2 cm in cross section.