Saint-Aubin is a rare European iron meteorite that was first found in France in 1968 by farmers plowing a field. It is an ungrouped octahedrite, meaning it does not fit into any existing iron meteorite class. Months of laboratory work were required to prepare the mass from which these slices were taken. It has not just been cut, polished, and etched, but also meticulously stabilized by an expert in meteorite preservation and preparation.
As noted in the The Meteoritical Bulletin, Saint-Aubin can display shock features, Neumann lines, iron sulfide nodules, and extraordinary schreibersite needles up to 6 centimeters in length. Schreibersite is a rare nickel-iron phosphide mineral that — apart from a single location in Greenland — is not found on Earth, but only in meteorites.