Lieksa        63°24.382’N, 30°04.227’E

Pohjois-Karjala, Finland

Find: 2017 May 30

Classification: Pallasite (ungrouped)

History: Pekka Vallimies discovered a rust-covered rock as a potential ore specimen in the area of Löpönvaara, Finland, ~10 km from Lieksa. After removing the rust with a wire brush, Vallimies thought it may be a meteorite and submitted the find to the Geological Survey of Finland (GTK). Examination, led by Dr. Kari Kinnunen, confirmed a meteoritic origin, and Vallimies donated this 238 g stone to the meteorite collection of the Finnish Museum of Natural History LUOMUS on May 30, 2018. Numerous smaller pieces of meteorite (up to 27.1 g) have been subsequently discovered in the find area.

Petrography: (Arto Luttinen) The sample was examined by x-ray tomography and was shown to be a mixture of ~80% metal and ~20% rounded silicates (3 mm in size) and oxides. Significant weathering around the edges and in cracks.

Geochemistry: Olivine Fa_23.0±0.1 (n=3). Metal: kamacite Ni 4.8-6.7%; taenite 30.9-38.1% Ni. Siderophile Chemistry LA-ICP-MS (average of 5 rasters, 5 mm long and 100 µm wide each) Fe 88.6%, Ni=10.6%, Co=0.7%. All other elements in ppm: Ga=2.1, Ge=58.1, As=4.8, Au=0.7. Highly siderophile elements by isotope dilution: Re=0.60 ppm, Os=7.99 ppm, Ir=7.77 ppm Ru=10.24 ppm, Pt=13.76 ppm, Pd=3.44 ppm. EPMA, LA-ICP-MS and ID HSE analyses were carried out at UMd (R.D. Ash, E.M. Chiappe, RJ. Walker).

Classification: Pallasite (ungrouped). The olivine is more fayalitic than other pallasites and the Ge/Ga ratio significantly higher