Burns        39°52’N, 106°53’W

Eagle County, Colorado, USA

Found: July 2003

Classification: Iron meteorite (IIIAB)

History: In July 2003, Gene Killinen was practicing with his new metal detector at his family’s hunting cabin near Burns, Colorado. Gene found a strong signal in the area immediately in front of the cabin. He and his father excavated a mass from a depth of roughly 60-90 cm. They surmised that the large, heavy object might be a meteorite, but they were uncertain. A year later they took the object to Fort Lewis College, where a nickel test was performed, with positive results. A sample was sent to Randy Korotev, WUSL, who confirmed that the specimen was a meteorite and an octahedrite. Anne Black purchased the meteorite in September of 2006, and it was subsequently sold to Peter Utas at the Tucson Gem and Mineral Show in 2007.

Physical characteristics: The meteorite weighs approximately 18.4 kg and has a flattened, highly irregular shape, and craggy surface covered with a thin layer of oxide and caliche. Several phosphide and sulfide inclusions are visible on the surface.

Petrography: Bandwidth ~0.24±0.05 mm, thus Of. Recrystallized, 0.2 × 0.04 kamacite grains in many plessite fields, borders of kamacite bands are ragged, not straight. Schreibersite is present on centers of many bands, mostly reaching sizes of 0.2-0.5 long by 0.05-0.1 thick. One hieroglyphic schreibersite 2 mm thick by 16 mm long, is sandwiched by swathing kamacite bar that reaches a thickness of 6 mm. Several kamacite recrystallized with some tiny taenites (or schreibersites). Weathering moderate, but confined to surface and near surface. No FeS recognized. No heat altered zone.

Geochemistry: Composition: 5.69 mg/g Co, 103.7 mg/g Ni, 14.4 μg/g Ga, ~28 μg/g Ge, 23.4 μg/g As, 0.022 μg/g Ir, and 2.588 μg/g Au. Burns falls near the high-Au extreme of group IIIAB; it has the second highest Au and Ni, the third-highest As and the highest Co in the UCLA IIIAB data set. The Saint-Aubin meteorite has the highest Au, Ni and As contents. The other irons that are closely similar to these two are Tieraco Creek, Thurlow and Bella Roca.

Classification: IIIAB

Specimens: 80 g at UCLA.