“Secondary electron image of a native rhenium particle, measuring 20×25 μm, from the the lower part of the transitional clay layer at the Cretaceous/Tertiary boundary in Gams 2 section. The grain has a prominent triangular shape with a ragged boundary and a crack (likely of thermal origin) at the top. The observer-facing edge shows a distinct porous texture probably related to degassing in the course of cooling. The particle composition is quite similar to that of pure rhenium with traces of Fe. Image from Grachev, A.F., Borisovsky, S.E., and Grigor'eva, A.V. (2008) The first find of native rhenium in the transitional clay layer at the Cretaceous/Paleogene boundary in the Gams section (Eastern Alps, Austria). Doklady Earth Sciences, 422(7), 1065-1067.”