10 Francs Lion, iridium

Iridium is one of the densest and most corrosion-resistant elements on earth, and among the rarest in the Earth's crust — more associated with asteroid impact layers than with mint production runs. Rwanda's use of it here is largely a novelty play, positioning the National Bank within the small collector market for exotic-metal issues that expanded noticeably in the 2010s. No iridium coin circulated. None was meant to.

KM#97 is sparsely documented in standard references, with mintage figures difficult to independently verify — not unusual for low-volume exotic issues from smaller issuing authorities in this period.