Unusual, 2.9" K-T Boundary Iridium Chalk - Denmark

This is a 2.9" chunk of iridium chalk from Denmark. This chalk is most likely from the Stevns Klint Cliffs that very clearly shows the stratigraphic line that marks the boundary between the Cretaceous and Paleogene (Tertiary) periods, roughly 66 million years ago. Global geology presents a thin line that is extremely rich in iridium thought to result from the Chicxulub impact that wiped out the non-avian dinosaurs. A very cool and unusual specimen.