Pseudometeorite from Łapino (Pomerania, North Poland)

A boulder, found in a gravel pit by Łapino near Gdańsk in 1954, was noted as unusual. Among various erratics ice-derived from Scandinavia in the Quaternary, this one had an extraordinary appearance; unusually dark, heavy and strongly magnetic. An extraterrestrial origin was suggested. The border resembles an intrusive breccia with numerous periclase-bearing fragments in a magnetite-clinopyroxene-olivine matrix. A single grain with a metallic luster, a few centimetres in diameter, was identified as the iron silicide (Fe3Si). Only two natural occurrences of iron silicide have been described, both from meteorites. However, the isotopic analysis showed an absence of radiogenic nuclides (10Be, 26Al, 36Cl), and the ratio of oxygen isotopes (delta 17O and delta 18O) suggested a terrestrial origin. Thus the stone is probable artifact, presumably the product of an unidentified foundry.