1/2 Dollar - Elizabeth II Apollo 16

Apollo 16 is often overshadowed by the moon landings that bracketed it, but the April 1972 mission produced one of the more scientifically consequential results of the program — the discovery that the lunar highlands are composed primarily of anorthosite, rewriting assumptions about the Moon's formation. Commander John Young and Charles Duke spent over 71 hours on the surface, the longest EVA total of any mission to that point.

Solomon Islands has issued commemorative silver-plated pieces under Elizabeth II's effigy for decades, functioning essentially as the numismatic licensing vehicle of choice for third-party bullion and collector series with no domestic circulation intent.